Implementierung für M2 vorläufig abgeschlossen

.claude/settings.local.json

@@ -2,7 +2,11 @@
   "permissions": {
     "allow": [
       "Bash(xargs grep:*)",
-      "Bash(xargs wc:*)"
+      "Bash(xargs wc:*)",
+      "Bash(mvn clean:*)",
+      "Bash(mvn verify:*)",
+      "Bash(mvn test:*)",
+      "Bash(find D:/Dev/Projects/pdf-umbenenner-parent -not -path */target/* -type d)"
     ]
   }
 }

pdf-umbenenner-adapter-in-cli/src/main/java/de/gecheckt/pdf/umbenenner/adapter/inbound/cli/SchedulerBatchCommand.java

@@ -1,12 +1,28 @@
 package de.gecheckt.pdf.umbenenner.adapter.inbound.cli;
 
+import de.gecheckt.pdf.umbenenner.application.port.in.BatchRunOutcome;
 import de.gecheckt.pdf.umbenenner.application.port.in.RunBatchProcessingUseCase;
+import de.gecheckt.pdf.umbenenner.domain.model.BatchRunContext;
 
 /**
  * CLI command adapter for batch processing scheduling.
  * <p>
- * This class acts as the technical entry point that delegates to the application layer.
+ * This class acts as the inbound technical entry point that exclusively delegates
+ * to the application layer's batch processing use case via the {@link RunBatchProcessingUseCase}
+ * interface. It receives the batch run outcome and makes it available to the Bootstrap layer
+ * for exit code determination and logging.
+ * <p>
  * AP-003 Implementation: Minimal no-op command to validate the call chain from CLI to Application.
+ * <p>
+ * M2-AP-002 Update: Returns {@link BatchRunOutcome} instead of boolean,
+ * allowing Bootstrap to systematically derive exit codes (AP-007).
+ * <p>
+ * M2-AP-003 Update: Accepts {@link BatchRunContext} and passes it to the use case,
+ * enabling run ID and timing tracking throughout the batch cycle.
+ * <p>
+ * M2-AP-005 Update: Dependency inversion achieved - this adapter depends only on the
+ * RunBatchProcessingUseCase interface, not on any concrete implementation. Bootstrap
+ * is responsible for injecting the appropriate use case implementation.
  */
 public class SchedulerBatchCommand {
 
@@ -22,13 +38,14 @@ public class SchedulerBatchCommand {
     }
 
     /**
-     * Executes the batch processing command.
+     * Executes the batch processing command with the given run context.
      * <p>
-     * AP-003: Delegates to the use case without any additional logic.
+     * Delegates to the use case with the batch run context and returns its structured outcome.
      *
-     * @return true if execution succeeded, false otherwise
+     * @param context the technical context for this batch run
+     * @return {@link BatchRunOutcome} describing the result of batch processing
      */
-    public boolean run() {
+    public BatchRunOutcome run(BatchRunContext context) {
-        return useCase.execute();
+        return useCase.execute(context);
     }
 }

pdf-umbenenner-adapter-in-cli/src/main/java/de/gecheckt/pdf/umbenenner/adapter/inbound/cli/package-info.java

@@ -1,7 +1,22 @@
 /**
- * CLI adapter for inbound commands.
+ * Inbound adapter for CLI/batch command processing.
- * This package contains the technical entry points that delegate to application use cases.
  * <p>
- * AP-003: Contains minimal command classes for validating the startup path.
+ * This package contains the technical entry points that delegate exclusively to application
+ * use cases via their inbound port interfaces. The adapter enforces strict dependency inversion:
+ * it depends on the application's inbound port contracts, not on concrete implementations.
+ * <p>
+ * Components:
+ * <ul>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.adapter.inbound.cli.SchedulerBatchCommand}
+ *       — CLI entry point that delegates to RunBatchProcessingUseCase interface (AP-005)</li>
+ * </ul>
+ * <p>
+ * M2-AP-005 Architecture:
+ * <ul>
+ *   <li>Adapter depends on: {@link de.gecheckt.pdf.umbenenner.application.port.in.RunBatchProcessingUseCase} (interface)</li>
+ *   <li>Adapter does not depend on: any concrete use case implementation</li>
+ *   <li>Bootstrap wires concrete use case implementation via constructor injection</li>
+ *   <li>Dependency direction: Adapter IN → (through port) → Application</li>
+ * </ul>
  */
 package de.gecheckt.pdf.umbenenner.adapter.inbound.cli;

pdf-umbenenner-adapter-in-cli/src/test/java/de/gecheckt/pdf/umbenenner/adapter/inbound/cli/SchedulerBatchCommandTest.java

@@ -0,0 +1,154 @@
+package de.gecheckt.pdf.umbenenner.adapter.inbound.cli;
+
+import de.gecheckt.pdf.umbenenner.application.port.in.BatchRunOutcome;
+import de.gecheckt.pdf.umbenenner.application.port.in.RunBatchProcessingUseCase;
+import de.gecheckt.pdf.umbenenner.domain.model.BatchRunContext;
+import de.gecheckt.pdf.umbenenner.domain.model.RunId;
+
+import org.junit.jupiter.api.Test;
+
+import java.time.Instant;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Unit tests for {@link SchedulerBatchCommand}.
+ * <p>
+ * Verifies that the CLI adapter correctly delegates to the batch processing use case
+ * and returns the outcome without transformation.
+ */
+class SchedulerBatchCommandTest {
+
+    @Test
+    void constructor_acceptsRunBatchProcessingUseCase() {
+        RunBatchProcessingUseCase mockUseCase = (context) -> BatchRunOutcome.SUCCESS;
+
+        SchedulerBatchCommand command = new SchedulerBatchCommand(mockUseCase);
+
+        assertNotNull(command, "Constructor should create a valid SchedulerBatchCommand");
+    }
+
+    @Test
+    void run_delegatesToUseCaseAndReturnsOutcome() {
+        // Setup: mock use case that returns SUCCESS
+        RunBatchProcessingUseCase mockUseCase = (context) -> BatchRunOutcome.SUCCESS;
+
+        SchedulerBatchCommand command = new SchedulerBatchCommand(mockUseCase);
+        BatchRunContext context = new BatchRunContext(new RunId("test-run"), Instant.now());
+
+        // Execute
+        BatchRunOutcome outcome = command.run(context);
+
+        // Verify
+        assertEquals(BatchRunOutcome.SUCCESS, outcome);
+    }
+
+    @Test
+    void run_passesContextToUseCase() {
+        RunId expectedRunId = new RunId("test-run-123");
+        Instant expectedStartTime = Instant.now();
+
+        // Setup: mock use case that captures the context
+        MockCapturingUseCase mockUseCase = new MockCapturingUseCase();
+
+        SchedulerBatchCommand command = new SchedulerBatchCommand(mockUseCase);
+        BatchRunContext context = new BatchRunContext(expectedRunId, expectedStartTime);
+
+        // Execute
+        command.run(context);
+
+        // Verify context was passed correctly
+        assertNotNull(mockUseCase.capturedContext);
+        assertEquals(expectedRunId, mockUseCase.capturedContext.runId());
+        assertEquals(expectedStartTime, mockUseCase.capturedContext.startInstant());
+    }
+
+    @Test
+    void run_returnsSuccessOutcome() {
+        RunBatchProcessingUseCase successUseCase = (context) -> BatchRunOutcome.SUCCESS;
+        SchedulerBatchCommand command = new SchedulerBatchCommand(successUseCase);
+        BatchRunContext context = new BatchRunContext(new RunId("test"), Instant.now());
+
+        BatchRunOutcome outcome = command.run(context);
+
+        assertEquals(BatchRunOutcome.SUCCESS, outcome);
+        assertTrue(outcome.isSuccess());
+        assertFalse(outcome.isFailure());
+    }
+
+    @Test
+    void run_returnsFailureOutcome() {
+        RunBatchProcessingUseCase failureUseCase = (context) -> BatchRunOutcome.FAILURE;
+        SchedulerBatchCommand command = new SchedulerBatchCommand(failureUseCase);
+        BatchRunContext context = new BatchRunContext(new RunId("test"), Instant.now());
+
+        BatchRunOutcome outcome = command.run(context);
+
+        assertEquals(BatchRunOutcome.FAILURE, outcome);
+        assertTrue(outcome.isFailure());
+        assertFalse(outcome.isSuccess());
+    }
+
+    @Test
+    void run_returnsLockUnavailableOutcome() {
+        RunBatchProcessingUseCase lockUnavailableUseCase = (context) -> BatchRunOutcome.LOCK_UNAVAILABLE;
+        SchedulerBatchCommand command = new SchedulerBatchCommand(lockUnavailableUseCase);
+        BatchRunContext context = new BatchRunContext(new RunId("test"), Instant.now());
+
+        BatchRunOutcome outcome = command.run(context);
+
+        assertEquals(BatchRunOutcome.LOCK_UNAVAILABLE, outcome);
+        assertTrue(outcome.isLockUnavailable());
+    }
+
+    @Test
+    void run_multipleCallsWithDifferentContexts() {
+        RunBatchProcessingUseCase mockUseCase = (context) -> BatchRunOutcome.SUCCESS;
+        SchedulerBatchCommand command = new SchedulerBatchCommand(mockUseCase);
+
+        BatchRunContext context1 = new BatchRunContext(new RunId("run-1"), Instant.now());
+        BatchRunContext context2 = new BatchRunContext(new RunId("run-2"), Instant.now());
+
+        // Execute multiple times
+        BatchRunOutcome outcome1 = command.run(context1);
+        BatchRunOutcome outcome2 = command.run(context2);
+
+        // Verify both succeed independently
+        assertEquals(BatchRunOutcome.SUCCESS, outcome1);
+        assertEquals(BatchRunOutcome.SUCCESS, outcome2);
+    }
+
+    @Test
+    void run_delegatesWithoutModifyingContext() {
+        RunId runId = new RunId("immutable-test");
+        Instant startTime = Instant.parse("2026-03-31T20:00:00Z");
+
+        RunBatchProcessingUseCase mockUseCase = (context) -> {
+            // Verify context state is not modified
+            assertEquals(runId, context.runId());
+            assertEquals(startTime, context.startInstant());
+            assertFalse(context.isCompleted());
+            return BatchRunOutcome.SUCCESS;
+        };
+
+        SchedulerBatchCommand command = new SchedulerBatchCommand(mockUseCase);
+        BatchRunContext context = new BatchRunContext(runId, startTime);
+
+        command.run(context);
+        // After run, context should still be incomplete (not modified by adapter)
+        assertFalse(context.isCompleted());
+    }
+
+    /**
+     * Mock use case that captures the passed context for verification.
+     */
+    private static class MockCapturingUseCase implements RunBatchProcessingUseCase {
+        BatchRunContext capturedContext;
+
+        @Override
+        public BatchRunOutcome execute(BatchRunContext context) {
+            this.capturedContext = context;
+            return BatchRunOutcome.SUCCESS;
+        }
+    }
+}

pdf-umbenenner-adapter-out/src/main/java/de/gecheckt/pdf/umbenenner/adapter/outbound/lock/FilesystemRunLockPortAdapter.java

@@ -0,0 +1,82 @@
+package de.gecheckt.pdf.umbenenner.adapter.outbound.lock;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import de.gecheckt.pdf.umbenenner.application.port.out.RunLockPort;
+import de.gecheckt.pdf.umbenenner.application.port.out.RunLockUnavailableException;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+
+/**
+ * File-based implementation of {@link RunLockPort} that uses a lock file to prevent concurrent runs.
+ * <p>
+ * AP-006 Implementation: Creates an exclusive lock file on acquire and deletes it on release.
+ * If the lock file already exists, {@link #acquire()} throws {@link RunLockUnavailableException}
+ * to signal that another instance is already running.
+ * <p>
+ * The lock file contains the PID of the acquiring process. Release is best-effort: a failure
+ * to delete the lock file is logged as a warning but does not throw.
+ */
+public class FilesystemRunLockPortAdapter implements RunLockPort {
+
+    private static final Logger LOG = LogManager.getLogger(FilesystemRunLockPortAdapter.class);
+
+    private final Path lockFile;
+
+    /**
+     * Creates a new FilesystemRunLockPortAdapter for the given lock file path.
+     *
+     * @param lockFile path of the lock file to create on acquire and delete on release
+     */
+    public FilesystemRunLockPortAdapter(Path lockFile) {
+        this.lockFile = lockFile;
+    }
+
+    /**
+     * Acquires the run lock by creating the lock file.
+     * <p>
+     * If the lock file already exists, throws {@link RunLockUnavailableException}.
+     * If the parent directory does not exist, it is created before attempting file creation.
+     *
+     * @throws RunLockUnavailableException if the lock file already exists or cannot be created
+     */
+    @Override
+    public void acquire() {
+        if (Files.exists(lockFile)) {
+            throw new RunLockUnavailableException(
+                    "Run lock file already exists - another instance may be running: " + lockFile);
+        }
+        try {
+            Path parent = lockFile.getParent();
+            if (parent != null) {
+                Files.createDirectories(parent);
+            }
+            long pid = ProcessHandle.current().pid();
+            Files.writeString(lockFile, String.valueOf(pid), StandardOpenOption.CREATE_NEW);
+            LOG.debug("Run lock acquired: {} (PID {})", lockFile, pid);
+        } catch (IOException e) {
+            throw new RunLockUnavailableException("Failed to acquire run lock file: " + lockFile, e);
+        }
+    }
+
+    /**
+     * Releases the run lock by deleting the lock file.
+     * <p>
+     * If deletion fails, a warning is logged but no exception is thrown.
+     */
+    @Override
+    public void release() {
+        try {
+            boolean deleted = Files.deleteIfExists(lockFile);
+            if (deleted) {
+                LOG.debug("Run lock released: {}", lockFile);
+            }
+        } catch (IOException e) {
+            LOG.warn("Failed to release run lock file: {} — manual cleanup may be required", lockFile, e);
+        }
+    }
+}

pdf-umbenenner-adapter-out/src/main/java/de/gecheckt/pdf/umbenenner/adapter/outbound/lock/package-info.java

@@ -0,0 +1,14 @@
+/**
+ * Outbound adapter for run lock management.
+ * <p>
+ * Components:
+ * <ul>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.adapter.outbound.lock.FilesystemRunLockPortAdapter}
+ *       — File-based run lock that prevents concurrent instances (AP-006)</li>
+ * </ul>
+ * <p>
+ * AP-006: Uses atomic file creation ({@code CREATE_NEW}) to establish an exclusive lock.
+ * Stores the acquiring process PID in the lock file for diagnostics.
+ * Release is best-effort and logs a warning on failure without throwing.
+ */
+package de.gecheckt.pdf.umbenenner.adapter.outbound.lock;

pdf-umbenenner-adapter-out/src/test/java/de/gecheckt/pdf/umbenenner/adapter/outbound/lock/FilesystemRunLockPortAdapterTest.java

@@ -0,0 +1,122 @@
+package de.gecheckt.pdf.umbenenner.adapter.outbound.lock;
+
+import de.gecheckt.pdf.umbenenner.application.port.out.RunLockUnavailableException;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Unit tests for {@link FilesystemRunLockPortAdapter}.
+ * <p>
+ * Tests cover acquire/release success path, lock contention behavior,
+ * and robust release behavior.
+ */
+class FilesystemRunLockPortAdapterTest {
+
+    @TempDir
+    Path tempDir;
+
+    @Test
+    void acquire_createsLockFile() {
+        Path lockFile = tempDir.resolve("test.lock");
+        FilesystemRunLockPortAdapter adapter = new FilesystemRunLockPortAdapter(lockFile);
+
+        adapter.acquire();
+
+        assertTrue(Files.exists(lockFile), "Lock file should exist after acquire");
+    }
+
+    @Test
+    void acquire_writesProcessPidToLockFile() throws Exception {
+        Path lockFile = tempDir.resolve("test.lock");
+        FilesystemRunLockPortAdapter adapter = new FilesystemRunLockPortAdapter(lockFile);
+
+        adapter.acquire();
+
+        String content = Files.readString(lockFile);
+        long pid = ProcessHandle.current().pid();
+        assertEquals(String.valueOf(pid), content, "Lock file should contain current PID");
+    }
+
+    @Test
+    void release_deletesLockFile() throws Exception {
+        Path lockFile = tempDir.resolve("test.lock");
+        FilesystemRunLockPortAdapter adapter = new FilesystemRunLockPortAdapter(lockFile);
+        adapter.acquire();
+        assertTrue(Files.exists(lockFile));
+
+        adapter.release();
+
+        assertFalse(Files.exists(lockFile), "Lock file should be deleted after release");
+    }
+
+    @Test
+    void release_doesNotThrowIfLockFileAbsent() {
+        Path lockFile = tempDir.resolve("nonexistent.lock");
+        FilesystemRunLockPortAdapter adapter = new FilesystemRunLockPortAdapter(lockFile);
+
+        assertDoesNotThrow(adapter::release, "Release without prior acquire should not throw");
+    }
+
+    @Test
+    void acquire_throwsRunLockUnavailableExceptionIfLockFileExists() throws Exception {
+        Path lockFile = tempDir.resolve("test.lock");
+        Files.writeString(lockFile, "12345");
+
+        FilesystemRunLockPortAdapter adapter = new FilesystemRunLockPortAdapter(lockFile);
+
+        assertThrows(RunLockUnavailableException.class, adapter::acquire,
+                "Acquire should throw RunLockUnavailableException when lock file already exists");
+    }
+
+    @Test
+    void acquire_exceptionMessageContainsLockFilePath() throws Exception {
+        Path lockFile = tempDir.resolve("test.lock");
+        Files.writeString(lockFile, "12345");
+
+        FilesystemRunLockPortAdapter adapter = new FilesystemRunLockPortAdapter(lockFile);
+
+        RunLockUnavailableException ex = assertThrows(RunLockUnavailableException.class, adapter::acquire);
+        assertTrue(ex.getMessage().contains(lockFile.toString()),
+                "Exception message should contain lock file path");
+    }
+
+    @Test
+    void acquire_createsParentDirectoriesIfAbsent() {
+        Path lockFile = tempDir.resolve("nested").resolve("deep").resolve("test.lock");
+        FilesystemRunLockPortAdapter adapter = new FilesystemRunLockPortAdapter(lockFile);
+
+        adapter.acquire();
+
+        assertTrue(Files.exists(lockFile), "Lock file should be created including parent dirs");
+    }
+
+    @Test
+    void acquireAndRelease_canBeRepeated() {
+        Path lockFile = tempDir.resolve("test.lock");
+        FilesystemRunLockPortAdapter adapter = new FilesystemRunLockPortAdapter(lockFile);
+
+        adapter.acquire();
+        adapter.release();
+        adapter.acquire();
+        adapter.release();
+
+        assertFalse(Files.exists(lockFile), "Lock file should not exist after second release");
+    }
+
+    @Test
+    void acquire_secondCallThrowsRunLockUnavailableException() {
+        Path lockFile = tempDir.resolve("test.lock");
+        FilesystemRunLockPortAdapter adapter = new FilesystemRunLockPortAdapter(lockFile);
+
+        adapter.acquire();
+
+        assertThrows(RunLockUnavailableException.class, adapter::acquire,
+                "Second acquire without release should throw RunLockUnavailableException");
+    }
+}

pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/port/in/BatchRunOutcome.java

@@ -0,0 +1,106 @@
+package de.gecheckt.pdf.umbenenner.application.port.in;
+
+/**
+ * Value object representing the outcome of a batch processing run.
+ * <p>
+ * This enum encodes the high-level result of executing a complete batch cycle,
+ * allowing Bootstrap and CLI layers to map outcomes to exit codes and log messages
+ * in a controlled and consistent manner.
+ * <p>
+ * The outcome is independent of individual document processing results;
+ * it represents the batch operation itself (lock acquired, no critical startup failure, etc.).
+ * <p>
+ * Design Note: This contract is defined in AP-002 to enable AP-007 (exit code handling)
+ * to derive exit codes systematically without requiring additional knowledge about
+ * the batch run. Each outcome maps cleanly to an exit code semantic.
+ * <p>
+ * AP-007: Three distinct outcomes are now defined to make the difference between a
+ * technically successful run, a controlled early termination due to start protection,
+ * and a hard bootstrap failure explicit in both code and logs.
+ *
+ * @since M2-AP-002
+ */
+public enum BatchRunOutcome {
+
+    /**
+     * Batch processing completed successfully.
+     * <p>
+     * The run acquired the lock, started cleanly, and completed the full processing cycle.
+     * Individual documents within the run may have succeeded or failed, but that is
+     * transparent to this outcome. The run itself executed as intended.
+     * <p>
+     * Maps to exit code 0.
+     */
+    SUCCESS("Batch processing completed successfully"),
+
+    /**
+     * Batch run aborted because another instance is already running.
+     * <p>
+     * The run lock could not be acquired because a concurrent instance holds it.
+     * This is a controlled, expected termination (start protection), not a hard failure.
+     * The new instance terminates immediately without performing any processing.
+     * <p>
+     * Maps to exit code 1.
+     *
+     * @since M2-AP-007
+     */
+    LOCK_UNAVAILABLE("Another instance is already running; this run terminates immediately"),
+
+    /**
+     * Batch processing failed due to an unexpected error.
+     * <p>
+     * The run encountered a critical error that prevented normal batch completion,
+     * such as an unrecoverable I/O error or infrastructure failure.
+     * <p>
+     * Maps to exit code 1.
+     */
+    FAILURE("Batch processing failed");
+
+    private final String message;
+
+    BatchRunOutcome(String message) {
+        this.message = message;
+    }
+
+    /**
+     * Returns a human-readable message for this outcome.
+     *
+     * @return descriptive message suitable for logging
+     */
+    public String message() {
+        return message;
+    }
+
+    /**
+     * Returns true if this outcome represents successful completion.
+     *
+     * @return true if outcome is {@link #SUCCESS}, false otherwise
+     */
+    public boolean isSuccess() {
+        return this == SUCCESS;
+    }
+
+    /**
+     * Returns true if this outcome represents any non-successful result.
+     * <p>
+     * Both {@link #FAILURE} and {@link #LOCK_UNAVAILABLE} are considered failures
+     * for the purpose of exit code derivation (both map to exit code 1).
+     * Use {@link #isLockUnavailable()} to distinguish the start-protection case.
+     *
+     * @return true if outcome is {@link #FAILURE} or {@link #LOCK_UNAVAILABLE}, false otherwise
+     */
+    public boolean isFailure() {
+        return this == FAILURE || this == LOCK_UNAVAILABLE;
+    }
+
+    /**
+     * Returns true if this outcome represents a controlled early termination due to
+     * the run lock being held by another instance.
+     *
+     * @return true if outcome is {@link #LOCK_UNAVAILABLE}, false otherwise
+     * @since M2-AP-007
+     */
+    public boolean isLockUnavailable() {
+        return this == LOCK_UNAVAILABLE;
+    }
+}

pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/port/in/RunBatchProcessingUseCase.java

@@ -1,18 +1,51 @@
 package de.gecheckt.pdf.umbenenner.application.port.in;
 
+import de.gecheckt.pdf.umbenenner.domain.model.BatchRunContext;
+
 /**
  * Inbound port for batch processing execution.
- * This interface defines the contract for triggering batch operations.
  * <p>
- * AP-003 Implementation: Currently a no-op placeholder to establish the technical startup path.
+ * This interface defines the contract for triggering batch operations.
+ * It is the central use case entry point for the entire application.
+ * <p>
+ * Responsibilities:
+ * <ul>
+ *   <li>Orchestrate the batch run lifecycle (start, process, end)</li>
+ *   <li>Interact with all outbound ports (lock, clock, configuration, persistence, etc.)</li>
+ *   <li>Return a structured outcome ({@link BatchRunOutcome}) that describes the run result</li>
+ * </ul>
+ * <p>
+ * The returned outcome is designed to be independent of individual document results,
+ * representing only the batch operation itself. Individual document successes/failures
+ * are tracked separately in persistence (future milestones).
+ * <p>
+ * M2-AP-002 Implementation:
+ * <ul>
+ *   <li>Port is defined with a structured return contract ({@link BatchRunOutcome})</li>
+ *   <li>Return model allows Bootstrap/CLI to systematically derive exit codes (AP-007)</li>
+ *   <li>No implementation of the use case itself yet (that is AP-004)</li>
+ * </ul>
+ * <p>
+ * M2-AP-003 Update:
+ * <ul>
+ *   <li>execute() now accepts a {@link BatchRunContext} containing the run ID and timing</li>
+ *   <li>The context flows through the entire batch cycle for correlation and logging</li>
+ * </ul>
  */
 public interface RunBatchProcessingUseCase {
+
     /**
      * Executes the batch processing workflow.
      * <p>
-     * AP-003: This method performs no actual work, only validates the call chain.
+     * The method orchestrates the entire batch cycle, from startup through completion.
+     * It interacts with all necessary outbound ports and returns a structured outcome.
+     * <p>
+     * The outcome is not dependent on how many documents succeeded or failed within the run;
+     * rather, it reflects the batch operation's overall health. Individual document results
+     * are recorded separately in persistence.
      *
-     * @return true if the workflow completed successfully, false otherwise
+     * @param context the technical context for this batch run, containing run ID and timing
+     * @return {@link BatchRunOutcome} indicating success or failure of the batch operation
      */
-    boolean execute();
+    BatchRunOutcome execute(BatchRunContext context);
 }

pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/port/in/package-info.java

@@ -1,5 +1,25 @@
 /**
- * Inbound ports (application service interfaces) for the hexagonal architecture.
+ * Inbound ports (use cases) for the application.
- * Use cases in this package are invoked by adapters from the outside world.
+ * <p>
+ * Inbound ports define the contracts for interacting with the application from external adapters.
+ * All calls flow FROM adapters INTO the application through these ports.
+ * <p>
+ * Central inbound port:
+ * <ul>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.application.port.in.RunBatchProcessingUseCase}
+ *       — The primary use case for executing a complete batch run</li>
+ * </ul>
+ * <p>
+ * Return models:
+ * <ul>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.application.port.in.BatchRunOutcome}
+ *       — Structured result of a batch run, designed for exit code mapping (AP-007)</li>
+ * </ul>
+ * <p>
+ * Architecture Rule: Inbound ports are independent of implementation and contain no business logic.
+ * They define "what can be done to the application". All dependencies point inward;
+ * adapters depend on ports, not vice versa.
+ *
+ * @since M2-AP-002
  */
 package de.gecheckt.pdf.umbenenner.application.port.in;

pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/port/out/ClockPort.java

@@ -0,0 +1,34 @@
+package de.gecheckt.pdf.umbenenner.application.port.out;
+
+import java.time.Instant;
+
+/**
+ * Outbound port for system time access.
+ * <p>
+ * This port abstracts access to the system clock, enabling the batch run to:
+ * <ul>
+ *   <li>Record timestamps for batch run start and completion</li>
+ *   <li>Generate or verify document timestamps (later in M5+)</li>
+ *   <li>Support testing with controlled time values</li>
+ * </ul>
+ * <p>
+ * By isolating time access behind a port, the application can be tested with
+ * deterministic time values without requiring system clock manipulation.
+ * <p>
+ * This port is defined in M2 for use in later milestones where timestamps
+ * become relevant (e.g., run history, document date fallback).
+ *
+ * @since M2-AP-002
+ */
+public interface ClockPort {
+
+    /**
+     * Returns the current moment in time.
+     * <p>
+     * Implementations should return the current system time (or a controlled test value).
+     * The returned instant is UTC-based and suitable for persistent storage and logging.
+     *
+     * @return the current instant
+     */
+    Instant now();
+}

pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/port/out/RunLockPort.java

@@ -0,0 +1,58 @@
+package de.gecheckt.pdf.umbenenner.application.port.out;
+
+/**
+ * Outbound port for exclusive run locking.
+ * <p>
+ * This port abstracts the mechanism for ensuring that only one instance of the PDF Umbenenner
+ * is executing at any given time. The port defines the contract without prescribing the
+ * implementation (e.g., file-based locks, OS-level locks, distributed locks).
+ * <p>
+ * Responsibilities:
+ * <ul>
+ *   <li>Guarantee exclusive access to shared resources (SQLite database, target directory)</li>
+ *   <li>Prevent concurrent batch runs from overwriting each other's work or causing inconsistencies</li>
+ *   <li>Allow controlled startup failure if another instance is already running</li>
+ * </ul>
+ * <p>
+ * Lock Lifecycle:
+ * <ul>
+ *   <li>Acquire the lock at batch startup (before any processing)</li>
+ *   <li>Hold the lock for the entire batch run</li>
+ *   <li>Release the lock cleanly at batch end (even on failure, if possible)</li>
+ * </ul>
+ * <p>
+ * This port is used by the batch use case (M2-AP-004) but not implemented in M2;
+ * implementation follows in M2-AP-006.
+ *
+ * @since M2-AP-002
+ */
+public interface RunLockPort {
+
+    /**
+     * Acquires an exclusive lock for the batch run.
+     * <p>
+     * This method blocks or throws an exception if the lock cannot be acquired
+     * (e.g., another instance already holds it). The behavior depends on the implementation.
+     * <p>
+     * If this method returns normally, the caller holds the lock and must ensure
+     * {@link #release()} is called to free it, typically in a finally block.
+     *
+     * @throws RunLockUnavailableException if the lock cannot be acquired
+     *         (e.g., another instance already holds it or system error prevents acquiring)
+     * @throws RuntimeException for other critical lock-related failures
+     */
+    void acquire();
+
+    /**
+     * Releases the exclusive lock held by this batch run.
+     * <p>
+     * This method is called after batch processing completes (successfully or not)
+     * to allow other instances to run.
+     * <p>
+     * Implementations should handle the case where release is called multiple times
+     * or when no lock is currently held, avoiding exceptions if possible.
+     *
+     * @throws RuntimeException if lock release fails critically
+     */
+    void release();
+}

pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/port/out/RunLockUnavailableException.java

@@ -0,0 +1,35 @@
+package de.gecheckt.pdf.umbenenner.application.port.out;
+
+/**
+ * Exception thrown when the run lock cannot be acquired.
+ * <p>
+ * This indicates that another instance of the PDF Umbenenner is already running
+ * and holding the exclusive lock. The current instance should terminate immediately
+ * and allow the running instance to complete.
+ * <p>
+ * This is a controlled failure mode, not a programming error. Applications should
+ * catch this exception and exit gracefully with the appropriate exit code.
+ *
+ * @since M2-AP-002
+ */
+public class RunLockUnavailableException extends RuntimeException {
+
+    /**
+     * Creates a new RunLockUnavailableException with the given message.
+     *
+     * @param message description of why the lock could not be acquired
+     */
+    public RunLockUnavailableException(String message) {
+        super(message);
+    }
+
+    /**
+     * Creates a new RunLockUnavailableException with the given message and cause.
+     *
+     * @param message description of why the lock could not be acquired
+     * @param cause the underlying exception that prevented lock acquisition
+     */
+    public RunLockUnavailableException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/port/out/package-info.java

@@ -1,5 +1,29 @@
 /**
- * Outbound ports for the application layer.
+ * Outbound ports (interfaces) for the application.
- * Defines interfaces for infrastructure access from the application layer.
+ * <p>
+ * Outbound ports define the contracts for interacting with external systems and infrastructure.
+ * All calls flow FROM the application OUT TO infrastructure adapters through these ports.
+ * <p>
+ * M2-AP-002 ports:
+ * <ul>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.application.port.out.ConfigurationPort}
+ *       — Loading application startup configuration (already M1)</li>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.application.port.out.RunLockPort}
+ *       — Exclusive run lock for preventing concurrent batch instances</li>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.application.port.out.ClockPort}
+ *       — System time access for timestamps and run context</li>
+ * </ul>
+ * <p>
+ * Exception types:
+ * <ul>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.application.port.out.RunLockUnavailableException}
+ *       — Thrown when run lock cannot be acquired (another instance running)</li>
+ * </ul>
+ * <p>
+ * Architecture Rule: Outbound ports are implementation-agnostic and contain no business logic.
+ * They define "what the application depends on externally". All dependencies point inward;
+ * the application depends on ports, adapters implement ports.
+ *
+ * @since M2-AP-002
  */
 package de.gecheckt.pdf.umbenenner.application.port.out;

pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/usecase/M2BatchRunProcessingUseCase.java

@@ -0,0 +1,104 @@
+package de.gecheckt.pdf.umbenenner.application.usecase;
+
+import de.gecheckt.pdf.umbenenner.application.config.StartConfiguration;
+import de.gecheckt.pdf.umbenenner.application.port.in.BatchRunOutcome;
+import de.gecheckt.pdf.umbenenner.application.port.in.RunBatchProcessingUseCase;
+import de.gecheckt.pdf.umbenenner.application.port.out.ConfigurationPort;
+import de.gecheckt.pdf.umbenenner.application.port.out.RunLockPort;
+import de.gecheckt.pdf.umbenenner.application.port.out.RunLockUnavailableException;
+import de.gecheckt.pdf.umbenenner.domain.model.BatchRunContext;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+/**
+ * M2 implementation of {@link RunBatchProcessingUseCase}.
+ * <p>
+ * This use case orchestrates the batch processing workflow with start protection
+ * and controlled execution lifecycle, but without actual document processing.
+ * <p>
+ * Responsibilities:
+ * <ul>
+ *   <li>Acquire exclusive run lock to prevent concurrent instances</li>
+ *   <li>Initialize batch execution with the provided run context</li>
+ *   <li>Coordinate outbound port interactions (configuration, lock management)</li>
+ *   <li>Release lock and finish cleanly regardless of execution path</li>
+ *   <li>Return structured outcome for Bootstrap exit code mapping</li>
+ * </ul>
+ * <p>
+ * M2 Non-Goals (not implemented):
+ * <ul>
+ *   <li>No source folder scanning</li>
+ *   <li>No PDF filtering or text extraction</li>
+ *   <li>No fingerprinting</li>
+ *   <li>No SQLite persistence</li>
+ *   <li>No AI integration</li>
+ *   <li>No filename generation</li>
+ *   <li>No target file copying</li>
+ *   <li>No business-level retry logic</li>
+ *   <li>No single-document processing</li>
+ * </ul>
+ *
+ * @since M2-AP-004
+ */
+public class M2BatchRunProcessingUseCase implements RunBatchProcessingUseCase {
+
+    private static final Logger LOG = LogManager.getLogger(M2BatchRunProcessingUseCase.class);
+
+    private final ConfigurationPort configurationPort;
+    private final RunLockPort runLockPort;
+
+    /**
+     * Creates the M2 batch use case with required outbound ports.
+     *
+     * @param configurationPort for loading startup configuration
+     * @param runLockPort for exclusive run locking
+     * @throws NullPointerException if any port is null
+     */
+    public M2BatchRunProcessingUseCase(ConfigurationPort configurationPort, RunLockPort runLockPort) {
+        this.configurationPort = configurationPort;
+        this.runLockPort = runLockPort;
+    }
+
+    @Override
+    public BatchRunOutcome execute(BatchRunContext context) {
+        LOG.info("M2 batch processing initiated with RunId: {}", context.runId());
+
+        try {
+            // Step 1: Acquire exclusive run lock (prevents concurrent instances)
+            try {
+                runLockPort.acquire();
+                LOG.debug("Run lock acquired successfully.");
+            } catch (RunLockUnavailableException e) {
+                LOG.warn("Run lock not available – another instance is already running. This instance terminates immediately.");
+                return BatchRunOutcome.LOCK_UNAVAILABLE;
+            }
+
+            // Step 2: Load configuration (already validated in Bootstrap, but accessible to use case)
+            StartConfiguration config = configurationPort.loadConfiguration();
+            LOG.debug("Configuration available: source={}, target={}", config.sourceFolder(), config.targetFolder());
+
+            // Step 3: M2 Batch execution frame (no document processing)
+            LOG.info("Batch execution frame initialized - RunId: {}, Start: {}", context.runId(), context.startInstant());
+
+            // M2 Non-goal: No source folder scanning, PDF processing, persistence, or filename generation
+            // This is a controlled no-op batch cycle that validates the entire orchestration path.
+
+            LOG.info("Batch execution frame completed successfully");
+            return BatchRunOutcome.SUCCESS;
+
+        } catch (Exception e) {
+            // Unexpected error during batch orchestration
+            LOG.error("Unexpected error during batch processing", e);
+            return BatchRunOutcome.FAILURE;
+        } finally {
+            // Step 4: Always release the run lock (critical for M2 start protection)
+            try {
+                runLockPort.release();
+                LOG.debug("Run lock released");
+            } catch (Exception e) {
+                LOG.warn("Warning: Failed to release run lock", e);
+            }
+        }
+    }
+}

pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/usecase/NoOpRunBatchProcessingUseCase.java

@@ -1,8 +1,10 @@
 package de.gecheckt.pdf.umbenenner.application.usecase;
 
 import de.gecheckt.pdf.umbenenner.application.config.StartConfiguration;
+import de.gecheckt.pdf.umbenenner.application.port.in.BatchRunOutcome;
 import de.gecheckt.pdf.umbenenner.application.port.in.RunBatchProcessingUseCase;
 import de.gecheckt.pdf.umbenenner.application.port.out.ConfigurationPort;
+import de.gecheckt.pdf.umbenenner.domain.model.BatchRunContext;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -14,6 +16,11 @@ import org.apache.logging.log4j.Logger;
  * without any business logic, PDF processing, or infrastructure access.
  * <p>
  * AP-005: Accepts {@link ConfigurationPort} to load typed startup configuration.
+ * <p>
+ * M2-AP-002 Update: Returns {@link BatchRunOutcome} instead of boolean,
+ * enabling structured result handling by Bootstrap and CLI layers.
+ * <p>
+ * M2-AP-003 Update: Accepts {@link BatchRunContext} to enable run ID and timing tracking.
  */
 public class NoOpRunBatchProcessingUseCase implements RunBatchProcessingUseCase {
 
@@ -30,12 +37,16 @@ public class NoOpRunBatchProcessingUseCase implements RunBatchProcessingUseCase
     }
 
     @Override
-    public boolean execute() {
+    public BatchRunOutcome execute(BatchRunContext context) {
         // AP-005: Load configuration through the port (technical loading only)
         StartConfiguration config = configurationPort.loadConfiguration();
         LOG.info("Configuration loaded successfully. Source: {}, Target: {}", config.sourceFolder(), config.targetFolder());
 
+        // M2-AP-003: Log run context information for traceability
+        LOG.info("Batch run started with RunId: {}, started at: {}", context.runId(), context.startInstant());
+
         // AP-003: Intentional no-op - validates the technical call chain only
-        return true;
+        // M2-AP-002: Return structured outcome instead of boolean
+        return BatchRunOutcome.SUCCESS;
     }
 }

pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/usecase/package-info.java

@@ -1,5 +1,14 @@
 /**
  * Use case implementations that realize the inbound port contracts.
- * Currently contains minimal no-op implementations for AP-003 technical validation.
+ * <p>
+ * Implementations:
+ * <ul>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.application.usecase.NoOpRunBatchProcessingUseCase}
+ *       — Minimal no-op for technical validation without start protection</li>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.application.usecase.M2BatchRunProcessingUseCase}
+ *       — M2 production implementation with run lock and controlled batch cycle (AP-004)</li>
+ * </ul>
+ * <p>
+ * All implementations are infrastructure-agnostic and interact only through ports.
  */
 package de.gecheckt.pdf.umbenenner.application.usecase;

pdf-umbenenner-application/src/test/java/de/gecheckt/pdf/umbenenner/application/usecase/M2BatchRunProcessingUseCaseTest.java

@@ -0,0 +1,188 @@
+package de.gecheckt.pdf.umbenenner.application.usecase;
+
+import de.gecheckt.pdf.umbenenner.application.config.StartConfiguration;
+import de.gecheckt.pdf.umbenenner.application.port.in.BatchRunOutcome;
+import de.gecheckt.pdf.umbenenner.application.port.out.ConfigurationPort;
+import de.gecheckt.pdf.umbenenner.application.port.out.RunLockPort;
+import de.gecheckt.pdf.umbenenner.application.port.out.RunLockUnavailableException;
+import de.gecheckt.pdf.umbenenner.domain.model.BatchRunContext;
+import de.gecheckt.pdf.umbenenner.domain.model.RunId;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.net.URI;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.Instant;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Tests for {@link M2BatchRunProcessingUseCase}.
+ * <p>
+ * Verifies correct orchestration of the M2 batch cycle including lock management,
+ * configuration loading, and controlled execution flow.
+ */
+class M2BatchRunProcessingUseCaseTest {
+
+    @TempDir
+    Path tempDir;
+
+    @Test
+    void execute_successfullyAcquiresAndReleasesLock() {
+        // Setup mock ports that track invocations
+        MockRunLockPort lockPort = new MockRunLockPort();
+        MockConfigurationPort configPort = new MockConfigurationPort(tempDir);
+
+        M2BatchRunProcessingUseCase useCase = new M2BatchRunProcessingUseCase(configPort, lockPort);
+        BatchRunContext context = new BatchRunContext(new RunId("test-run-1"), Instant.now());
+
+        // Execute
+        BatchRunOutcome outcome = useCase.execute(context);
+
+        // Verify lock lifecycle
+        assertTrue(lockPort.wasAcquireCalled(), "Lock acquire should be called");
+        assertTrue(lockPort.wasReleaseCalled(), "Lock release should be called");
+        assertTrue(outcome.isSuccess(), "Batch should complete successfully");
+    }
+
+    @Test
+    void execute_returnsLockUnavailableWhenLockCannotBeAcquired() {
+        // Setup: lock port that fails to acquire (another instance is running)
+        RunLockPort lockPort = new RunLockPort() {
+            @Override
+            public void acquire() {
+                throw new RunLockUnavailableException("Another instance already running");
+            }
+
+            @Override
+            public void release() {
+                // Nothing to release
+            }
+        };
+
+        ConfigurationPort configPort = new MockConfigurationPort(tempDir);
+        M2BatchRunProcessingUseCase useCase = new M2BatchRunProcessingUseCase(configPort, lockPort);
+        BatchRunContext context = new BatchRunContext(new RunId("test-run-2"), Instant.now());
+
+        // Execute
+        BatchRunOutcome outcome = useCase.execute(context);
+
+        // AP-007: lock unavailable is a distinct, controlled early-termination outcome
+        assertTrue(outcome.isLockUnavailable(), "Outcome should be LOCK_UNAVAILABLE when lock cannot be acquired");
+        assertTrue(outcome.isFailure(), "LOCK_UNAVAILABLE also reports as failure for exit code derivation");
+        assertFalse(outcome.isSuccess(), "Batch should not succeed when lock unavailable");
+    }
+
+    @Test
+    void execute_releasesLockEvenOnError() {
+        // Setup: mock lock port that tracks release calls
+        MockRunLockPort lockPort = new MockRunLockPort();
+
+        // Config port that throws exception
+        ConfigurationPort configPort = () -> {
+            throw new RuntimeException("Configuration loading error");
+        };
+
+        M2BatchRunProcessingUseCase useCase = new M2BatchRunProcessingUseCase(configPort, lockPort);
+        BatchRunContext context = new BatchRunContext(new RunId("test-run-3"), Instant.now());
+
+        // Execute (expect failure due to config error)
+        BatchRunOutcome outcome = useCase.execute(context);
+
+        // Verify lock is still released despite error
+        assertTrue(lockPort.wasReleaseCalled(), "Lock should be released even on configuration error");
+        assertTrue(outcome.isFailure(), "Batch should fail");
+    }
+
+    @Test
+    void execute_loadsConfigurationDuringExecution() {
+        // Setup
+        MockRunLockPort lockPort = new MockRunLockPort();
+        MockConfigurationPort configPort = new MockConfigurationPort(tempDir);
+
+        M2BatchRunProcessingUseCase useCase = new M2BatchRunProcessingUseCase(configPort, lockPort);
+        BatchRunContext context = new BatchRunContext(new RunId("test-run-4"), Instant.now());
+
+        // Execute
+        BatchRunOutcome outcome = useCase.execute(context);
+
+        // Verify configuration was loaded
+        assertTrue(configPort.wasLoadConfigurationCalled(), "Configuration should be loaded");
+        assertTrue(outcome.isSuccess(), "Batch should succeed");
+    }
+
+    /**
+     * Mock ConfigurationPort for testing.
+     */
+    private static class MockConfigurationPort implements ConfigurationPort {
+        private final Path tempDir;
+        private boolean loadConfigurationCalled = false;
+
+        MockConfigurationPort(Path tempDir) {
+            this.tempDir = tempDir;
+        }
+
+        @Override
+        public StartConfiguration loadConfiguration() {
+            loadConfigurationCalled = true;
+
+            try {
+                Path sourceDir = Files.createDirectories(tempDir.resolve("source"));
+                Path targetDir = Files.createDirectories(tempDir.resolve("target"));
+                Path dbFile = Files.createFile(tempDir.resolve("db.sqlite"));
+                Path promptFile = Files.createFile(tempDir.resolve("prompt.txt"));
+
+                return new StartConfiguration(
+                        sourceDir,
+                        targetDir,
+                        dbFile,
+                        URI.create("https://api.example.com"),
+                        "gpt-4",
+                        30,
+                        3,
+                        100,
+                        50000,
+                        promptFile,
+                        tempDir.resolve("lock.lock"),
+                        tempDir.resolve("logs"),
+                        "INFO",
+                        "test-key"
+                );
+            } catch (Exception e) {
+                throw new RuntimeException("Failed to create mock configuration", e);
+            }
+        }
+
+        boolean wasLoadConfigurationCalled() {
+            return loadConfigurationCalled;
+        }
+    }
+
+    /**
+     * Mock RunLockPort for testing.
+     */
+    private static class MockRunLockPort implements RunLockPort {
+        private boolean acquireCalled = false;
+        private boolean releaseCalled = false;
+
+        @Override
+        public void acquire() {
+            acquireCalled = true;
+        }
+
+        @Override
+        public void release() {
+            releaseCalled = true;
+        }
+
+        boolean wasAcquireCalled() {
+            return acquireCalled;
+        }
+
+        boolean wasReleaseCalled() {
+            return releaseCalled;
+        }
+    }
+}

pdf-umbenenner-bootstrap/src/main/java/de/gecheckt/pdf/umbenenner/bootstrap/BootstrapRunner.java

@@ -5,11 +5,20 @@ import org.apache.logging.log4j.Logger;
 
 import de.gecheckt.pdf.umbenenner.adapter.inbound.cli.SchedulerBatchCommand;
 import de.gecheckt.pdf.umbenenner.adapter.outbound.configuration.PropertiesConfigurationPortAdapter;
+import de.gecheckt.pdf.umbenenner.adapter.outbound.lock.FilesystemRunLockPortAdapter;
 import de.gecheckt.pdf.umbenenner.application.config.InvalidStartConfigurationException;
 import de.gecheckt.pdf.umbenenner.application.config.StartConfigurationValidator;
+import de.gecheckt.pdf.umbenenner.application.port.in.BatchRunOutcome;
 import de.gecheckt.pdf.umbenenner.application.port.in.RunBatchProcessingUseCase;
 import de.gecheckt.pdf.umbenenner.application.port.out.ConfigurationPort;
-import de.gecheckt.pdf.umbenenner.application.usecase.NoOpRunBatchProcessingUseCase;
+import de.gecheckt.pdf.umbenenner.application.port.out.RunLockPort;
+import de.gecheckt.pdf.umbenenner.application.usecase.M2BatchRunProcessingUseCase;
+import de.gecheckt.pdf.umbenenner.domain.model.BatchRunContext;
+import de.gecheckt.pdf.umbenenner.domain.model.RunId;
+
+import java.nio.file.Path;
+import java.time.Instant;
+import java.util.UUID;
 
 /**
  * Manual bootstrap runner that constructs the object graph and drives the startup flow.
@@ -17,7 +26,7 @@ import de.gecheckt.pdf.umbenenner.application.usecase.NoOpRunBatchProcessingUseC
  * AP-003 Implementation: Creates all required components using plain Java constructor injection
  * and executes the minimal no-op batch processing path.
  * <p>
- * AP-005: Integrates configuration loading via PropertiesConfigurationPortAdapter.
+ * AP-005: CLI adapter and bootstrap wiring for M2 batch orchestration with run lock integration.
  * <p>
  * AP-006: Validates configuration before processing begins, returns exit code 1 on invalid config.
  */
@@ -26,6 +35,7 @@ public class BootstrapRunner {
     private static final Logger LOG = LogManager.getLogger(BootstrapRunner.class);
 
     private final ConfigurationPortFactory configPortFactory;
+    private final RunLockPortFactory runLockPortFactory;
     private final ValidatorFactory validatorFactory;
     private final UseCaseFactory useCaseFactory;
     private final CommandFactory commandFactory;
@@ -38,6 +48,14 @@ public class BootstrapRunner {
         ConfigurationPort create();
     }
 
+    /**
+     * Functional interface for creating a RunLockPort from the configured lock file path.
+     */
+    @FunctionalInterface
+    public interface RunLockPortFactory {
+        RunLockPort create(Path lockFilePath);
+    }
+
     /**
      * Functional interface for creating a StartConfigurationValidator.
      */
@@ -51,7 +69,7 @@ public class BootstrapRunner {
      */
     @FunctionalInterface
     public interface UseCaseFactory {
-        RunBatchProcessingUseCase create(ConfigurationPort configPort);
+        RunBatchProcessingUseCase create(ConfigurationPort configPort, RunLockPort runLockPort);
     }
 
     /**
@@ -64,11 +82,14 @@ public class BootstrapRunner {
 
     /**
      * Creates the BootstrapRunner with default factories for production use.
+     * <p>
+     * AP-006: Uses FilesystemRunLockPortAdapter for file-based exclusive run locking.
      */
     public BootstrapRunner() {
         this.configPortFactory = PropertiesConfigurationPortAdapter::new;
+        this.runLockPortFactory = FilesystemRunLockPortAdapter::new;
         this.validatorFactory = StartConfigurationValidator::new;
-        this.useCaseFactory = NoOpRunBatchProcessingUseCase::new;
+        this.useCaseFactory = M2BatchRunProcessingUseCase::new;
         this.commandFactory = SchedulerBatchCommand::new;
     }
 
@@ -76,15 +97,18 @@ public class BootstrapRunner {
      * Creates the BootstrapRunner with custom factories for testing.
      *
      * @param configPortFactory factory for creating ConfigurationPort instances
+     * @param runLockPortFactory factory for creating RunLockPort instances
      * @param validatorFactory factory for creating StartConfigurationValidator instances
      * @param useCaseFactory factory for creating RunBatchProcessingUseCase instances
      * @param commandFactory factory for creating SchedulerBatchCommand instances
      */
     public BootstrapRunner(ConfigurationPortFactory configPortFactory,
+                           RunLockPortFactory runLockPortFactory,
                            ValidatorFactory validatorFactory,
                            UseCaseFactory useCaseFactory,
                            CommandFactory commandFactory) {
         this.configPortFactory = configPortFactory;
+        this.runLockPortFactory = runLockPortFactory;
         this.validatorFactory = validatorFactory;
         this.useCaseFactory = useCaseFactory;
         this.commandFactory = commandFactory;
@@ -112,20 +136,37 @@ public class BootstrapRunner {
             StartConfigurationValidator validator = validatorFactory.create();
             validator.validate(config);
 
-            // Step 4: Create the use case with the configuration port (application layer)
+            // Step 4: Create the run lock port from the validated config (AP-006)
-            RunBatchProcessingUseCase useCase = useCaseFactory.create(configPort);
+            RunLockPort runLockPort = runLockPortFactory.create(config.runtimeLockFile());
 
-            // Step 5: Create the CLI command adapter with the use case
+            // Step 5: Create the batch run context (M2-AP-003)
+            // Generate a unique run ID and initialize the run context
+            RunId runId = new RunId(UUID.randomUUID().toString());
+            BatchRunContext runContext = new BatchRunContext(runId, Instant.now());
+            LOG.info("Batch run started. RunId: {}", runId);
+
+            // Step 6: Create the use case with the configuration port and run lock (application layer)
+            RunBatchProcessingUseCase useCase = useCaseFactory.create(configPort, runLockPort);
+
+            // Step 7: Create the CLI command adapter with the use case
             SchedulerBatchCommand command = commandFactory.create(useCase);
 
-            // Step 6: Execute the command
+            // Step 8: Execute the command with the run context and handle the outcome
-            boolean success = command.run();
+            BatchRunOutcome outcome = command.run(runContext);
 
-            if (success) {
+            // Mark run as completed (AP-003)
-                LOG.info("No-op startup path completed successfully.");
+            runContext.setEndInstant(Instant.now());
+
+            if (outcome.isSuccess()) {
+                LOG.info("Batch run completed successfully. RunId: {}", runContext.runId());
+                return 0;
+            } else if (outcome.isLockUnavailable()) {
+                LOG.warn("Batch run aborted: another instance is already running. RunId: {}", runContext.runId());
+                return 1;
+            } else {
+                LOG.error("Batch run failed. RunId: {}", runContext.runId());
+                return 1;
             }
-
-            return success ? 0 : 1;
         } catch (InvalidStartConfigurationException e) {
             // Controlled failure for invalid configuration - log clearly without stack trace
             LOG.error("Configuration validation failed: {}", e.getMessage());

pdf-umbenenner-bootstrap/src/main/java/de/gecheckt/pdf/umbenenner/bootstrap/package-info.java

@@ -1,7 +1,29 @@
 /**
- * Bootstrap module for application startup and technical wiring.
+ * Bootstrap module for application startup and technical object graph construction.
+ * <p>
+ * Responsibility: Orchestrate the startup flow, load configuration, validate it,
+ * create and wire all application components, and invoke the CLI adapter entry point.
+ * <p>
+ * Components:
+ * <ul>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.bootstrap.BootstrapRunner}
+ *       — Orchestrator of startup sequence and object graph construction (M2-AP-005)</li>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.bootstrap.PdfUmbenennerApplication}
+ *       — Main entry point that invokes BootstrapRunner (M1)</li>
+ * </ul>
+ * <p>
+ * M2 Implementation:
+ * <ul>
+ *   <li>Uses factory pattern with pluggable interfaces for all ports and use cases</li>
+ *   <li>Manually constructs object graph without framework dependencies</li>
+ *   <li>Ensures strict inward dependency direction toward application and domain</li>
+ *   <li>Ready for extension by later milestones via factory methods</li>
+ * </ul>
  * <p>
- * This package contains the main entry point and manual object graph construction.
  * AP-003: Provides a minimal, controlled startup path without dependency injection frameworks.
+ * <p>
+ * AP-005: CLI adapter and complete M2 object graph wiring.
+ * <p>
+ * AP-006: Wires FilesystemRunLockPortAdapter (adapter-out) from validated config; retired temporary no-op lock.
  */
 package de.gecheckt.pdf.umbenenner.bootstrap;

pdf-umbenenner-bootstrap/src/test/java/de/gecheckt/pdf/umbenenner/bootstrap/BootstrapRunnerTest.java

@@ -4,8 +4,11 @@ import de.gecheckt.pdf.umbenenner.adapter.inbound.cli.SchedulerBatchCommand;
 import de.gecheckt.pdf.umbenenner.application.config.InvalidStartConfigurationException;
 import de.gecheckt.pdf.umbenenner.application.config.StartConfiguration;
 import de.gecheckt.pdf.umbenenner.application.config.StartConfigurationValidator;
+import de.gecheckt.pdf.umbenenner.application.port.in.BatchRunOutcome;
 import de.gecheckt.pdf.umbenenner.application.port.in.RunBatchProcessingUseCase;
 import de.gecheckt.pdf.umbenenner.application.port.out.ConfigurationPort;
+import de.gecheckt.pdf.umbenenner.application.port.out.RunLockPort;
+import de.gecheckt.pdf.umbenenner.domain.model.BatchRunContext;
 
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
@@ -35,8 +38,9 @@ class BootstrapRunnerTest {
         // Create mock factories that return working components
         BootstrapRunner runner = new BootstrapRunner(
                 () -> mockConfigPort,
+                lockFile -> new MockRunLockPort(),
                 StartConfigurationValidator::new,
-                port -> new MockRunBatchProcessingUseCase(true),
+                (port, lock) -> new MockRunBatchProcessingUseCase(true),
                 useCase -> new SchedulerBatchCommand(useCase)
         );
 
@@ -60,8 +64,9 @@ class BootstrapRunnerTest {
 
         BootstrapRunner runner = new BootstrapRunner(
                 () -> mockConfigPort,
+                lockFile -> new MockRunLockPort(),
                 () -> failingValidator,
-                port -> new MockRunBatchProcessingUseCase(true),
+                (port, lock) -> new MockRunBatchProcessingUseCase(true),
                 useCase -> new SchedulerBatchCommand(useCase)
         );
 
@@ -79,8 +84,9 @@ class BootstrapRunnerTest {
 
         BootstrapRunner runner = new BootstrapRunner(
                 () -> failingConfigPort,
+                lockFile -> new MockRunLockPort(),
                 StartConfigurationValidator::new,
-                port -> new MockRunBatchProcessingUseCase(true),
+                (port, lock) -> new MockRunBatchProcessingUseCase(true),
                 useCase -> new SchedulerBatchCommand(useCase)
         );
 
@@ -98,8 +104,9 @@ class BootstrapRunnerTest {
 
         BootstrapRunner runner = new BootstrapRunner(
                 () -> throwingConfigPort,
+                lockFile -> new MockRunLockPort(),
                 StartConfigurationValidator::new,
-                port -> new MockRunBatchProcessingUseCase(true),
+                (port, lock) -> new MockRunBatchProcessingUseCase(true),
                 useCase -> new SchedulerBatchCommand(useCase)
         );
 
@@ -109,23 +116,45 @@ class BootstrapRunnerTest {
     }
 
     @Test
-    void run_returnsOneWhenCommandReturnsFalse() throws Exception {
+    void run_returnsOneWhenBatchFails() throws Exception {
         // Create a mock configuration port that returns valid config
         ConfigurationPort mockConfigPort = new MockConfigurationPort(tempDir, true);
 
-        // Create a use case that returns false
+        // Create a use case that returns failure outcome
-        RunBatchProcessingUseCase failingUseCase = () -> false;
+        RunBatchProcessingUseCase failingUseCase = (context) -> BatchRunOutcome.FAILURE;
 
         BootstrapRunner runner = new BootstrapRunner(
                 () -> mockConfigPort,
+                lockFile -> new MockRunLockPort(),
                 StartConfigurationValidator::new,
-                port -> failingUseCase,
+                (port, lock) -> failingUseCase,
                 useCase -> new SchedulerBatchCommand(useCase)
         );
 
         int exitCode = runner.run();
 
-        assertEquals(1, exitCode, "Command returning false should return exit code 1");
+        assertEquals(1, exitCode, "Batch failure outcome should return exit code 1");
+    }
+
+    @Test
+    void run_returnsOneWhenLockUnavailable() throws Exception {
+        // AP-007: controlled early termination because another instance is already running
+        // maps to exit code 1 (start protection counts as a hard startup failure)
+        ConfigurationPort mockConfigPort = new MockConfigurationPort(tempDir, true);
+
+        RunBatchProcessingUseCase lockUnavailableUseCase = (context) -> BatchRunOutcome.LOCK_UNAVAILABLE;
+
+        BootstrapRunner runner = new BootstrapRunner(
+                () -> mockConfigPort,
+                lockFile -> new MockRunLockPort(),
+                StartConfigurationValidator::new,
+                (port, lock) -> lockUnavailableUseCase,
+                useCase -> new SchedulerBatchCommand(useCase)
+        );
+
+        int exitCode = runner.run();
+
+        assertEquals(1, exitCode, "Lock unavailable (another instance running) should return exit code 1");
     }
 
     @Test
@@ -194,8 +223,23 @@ class BootstrapRunnerTest {
         }
 
         @Override
-        public boolean execute() {
+        public BatchRunOutcome execute(BatchRunContext context) {
-            return shouldSucceed;
+            return shouldSucceed ? BatchRunOutcome.SUCCESS : BatchRunOutcome.FAILURE;
+        }
+    }
+
+    /**
+     * Mock RunLockPort for testing.
+     */
+    private static class MockRunLockPort implements RunLockPort {
+        @Override
+        public void acquire() {
+            // Mock: no-op
+        }
+
+        @Override
+        public void release() {
+            // Mock: no-op
         }
     }
 }

pdf-umbenenner-domain/src/main/java/de/gecheckt/pdf/umbenenner/domain/model/BatchRunContext.java

@@ -0,0 +1,110 @@
+package de.gecheckt.pdf.umbenenner.domain.model;
+
+import java.time.Instant;
+import java.util.Objects;
+
+/**
+ * Technical context representing a single batch processing run.
+ * <p>
+ * Each batch run is assigned a unique {@link RunId} and has associated timestamp information.
+ * The context flows through the entire execution from Bootstrap through Use Case,
+ * enabling correlation of all activities and results within a single run.
+ * <p>
+ * Responsibilities:
+ * <ul>
+ *   <li>Track the unique identity of the batch run</li>
+ *   <li>Record when the run started (and eventually when it ends)</li>
+ *   <li>Provide run context to persistence, logging, and result tracking (future milestones)</li>
+ * </ul>
+ * <p>
+ * This context is independent of individual document processing and contains
+ * no business logic. It is purely a technical container for run identity and timing.
+ *
+ * @since M2-AP-003
+ */
+public final class BatchRunContext {
+
+    private final RunId runId;
+    private final Instant startInstant;
+    private Instant endInstant;
+
+    /**
+     * Creates a new BatchRunContext with the given run ID and start time.
+     * <p>
+     * The end instant is initially null and may be set later via {@link #setEndInstant(Instant)}.
+     *
+     * @param runId the unique identifier for this run, must not be null
+     * @param startInstant the moment when the run started, must not be null
+     * @throws NullPointerException if runId or startInstant is null
+     */
+    public BatchRunContext(RunId runId, Instant startInstant) {
+        this.runId = Objects.requireNonNull(runId, "RunId must not be null");
+        this.startInstant = Objects.requireNonNull(startInstant, "Start instant must not be null");
+        this.endInstant = null;
+    }
+
+    /**
+     * Returns the unique identifier of this run.
+     *
+     * @return the run ID, never null
+     */
+    public RunId runId() {
+        return runId;
+    }
+
+    /**
+     * Returns the instant when this run started.
+     *
+     * @return the start instant, never null
+     */
+    public Instant startInstant() {
+        return startInstant;
+    }
+
+    /**
+     * Returns the instant when this run ended, or null if the run has not yet completed.
+     * <p>
+     * The end instant is set by {@link #setEndInstant(Instant)} during run completion.
+     *
+     * @return the end instant, or null if the run is still in progress
+     */
+    public Instant endInstant() {
+        return endInstant;
+    }
+
+    /**
+     * Sets the instant when this run ended.
+     * <p>
+     * This should be called once at the end of the batch run to mark completion.
+     * Typically called by the orchestration layer (Bootstrap) after the use case completes.
+     *
+     * @param endInstant the moment when the run completed, must not be null
+     * @throws NullPointerException if endInstant is null
+     * @throws IllegalStateException if end instant has already been set
+     */
+    public void setEndInstant(Instant endInstant) {
+        Objects.requireNonNull(endInstant, "End instant must not be null");
+        if (this.endInstant != null) {
+            throw new IllegalStateException("End instant has already been set");
+        }
+        this.endInstant = endInstant;
+    }
+
+    /**
+     * Returns true if this run has completed (end instant is set).
+     *
+     * @return true if end instant is not null, false otherwise
+     */
+    public boolean isCompleted() {
+        return endInstant != null;
+    }
+
+    @Override
+    public String toString() {
+        return "BatchRunContext{" +
+                "runId=" + runId +
+                ", startInstant=" + startInstant +
+                ", endInstant=" + endInstant +
+                '}';
+    }
+}

pdf-umbenenner-domain/src/main/java/de/gecheckt/pdf/umbenenner/domain/model/ProcessingStatus.java

@@ -0,0 +1,79 @@
+package de.gecheckt.pdf.umbenenner.domain.model;
+
+/**
+ * Enumeration of all valid processing status values for a document within a batch run.
+ * <p>
+ * Each status reflects the outcome or current state of a document processing attempt.
+ * Status transitions follow the rules defined in the architecture specification and persist
+ * across multiple batch runs via the repository layer.
+ * <p>
+ * Status Categories:
+ * <ul>
+ *   <li><strong>Final Success:</strong> {@link #SUCCESS}</li>
+ *   <li><strong>Retryable Failure:</strong> {@link #FAILED_RETRYABLE}</li>
+ *   <li><strong>Final Failure:</strong> {@link #FAILED_FINAL}</li>
+ *   <li><strong>Skip (Already Processed):</strong> {@link #SKIPPED_ALREADY_PROCESSED}</li>
+ *   <li><strong>Skip (Final Failure):</strong> {@link #SKIPPED_FINAL_FAILURE}</li>
+ *   <li><strong>Processing (Transient):</strong> {@link #PROCESSING}</li>
+ * </ul>
+ *
+ * @since M2-AP-001
+ */
+public enum ProcessingStatus {
+
+    /**
+     * Document was successfully processed and written to the target location.
+     * <p>
+     * A document with this status will be skipped in all future batch runs.
+     * Status is final and irreversible.
+     */
+    SUCCESS,
+
+    /**
+     * Processing failed with a transient error (temporary infrastructure problem).
+     * <p>
+     * Examples: API timeout, temporary file lock, momentary network issue.
+     * <p>
+     * A document with this status may be retried in a later batch run, up to the
+     * configured maximum retry count. Retry count is tracked separately.
+     */
+    FAILED_RETRYABLE,
+
+    /**
+     * Processing failed with a deterministic content error (non-recoverable problem).
+     * <p>
+     * Examples: PDF has no extractable text, page limit exceeded, document is ambiguous.
+     * <p>
+     * A document with this status receives exactly one retry in a later batch run.
+     * After that retry, if it still fails, status becomes {@link #FAILED_FINAL}.
+     * No further retries are attempted.
+     */
+    FAILED_FINAL,
+
+    /**
+     * Document was skipped because it has already been successfully processed.
+     * <p>
+     * This is a final skip state. The document will remain skipped in all future runs.
+     * Document fingerprint matching ensures that identical content is never reprocessed.
+     */
+    SKIPPED_ALREADY_PROCESSED,
+
+    /**
+     * Document was skipped because it has already failed finally.
+     * <p>
+     * This is a final skip state. The document will remain skipped in all future runs.
+     * No further processing attempts will be made.
+     */
+    SKIPPED_FINAL_FAILURE,
+
+    /**
+     * Technical transient status: Document is currently being processed.
+     * <p>
+     * This status is used internally during a batch run to mark documents
+     * that are actively being worked on. If a batch run is interrupted,
+     * documents in this state will be re-attempted in the next run.
+     * <p>
+     * This status should not persist across batch runs in normal operation.
+     */
+    PROCESSING
+}

pdf-umbenenner-domain/src/main/java/de/gecheckt/pdf/umbenenner/domain/model/RunId.java

@@ -0,0 +1,73 @@
+package de.gecheckt.pdf.umbenenner.domain.model;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+/**
+ * Unique identifier for a batch run.
+ * <p>
+ * Each invocation of the PDF Umbenenner application receives a unique RunId
+ * that persists for the entire batch processing cycle. The RunId is used to:
+ * <ul>
+ *   <li>Correlate all documents processed in a single run</li>
+ *   <li>Track attempt history and retry decisions across runs</li>
+ *   <li>Identify logs and audit trails for a specific execution</li>
+ * </ul>
+ * <p>
+ * RunId is intentionally simple: a non-null, immutable string value.
+ * Implementations may choose UUID format, timestamp-based IDs, or sequential IDs.
+ * The internal structure is opaque to consumers.
+ *
+ * @since M2-AP-003
+ */
+public final class RunId implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    private final String value;
+
+    /**
+     * Creates a new RunId with the given string value.
+     * <p>
+     * The value must be non-null and non-empty. No format validation is enforced;
+     * implementations are free to choose their own ID scheme.
+     *
+     * @param value the unique identifier string, must not be null or empty
+     * @throws NullPointerException if value is null
+     * @throws IllegalArgumentException if value is empty
+     */
+    public RunId(String value) {
+        Objects.requireNonNull(value, "RunId value must not be null");
+        if (value.trim().isEmpty()) {
+            throw new IllegalArgumentException("RunId value must not be empty");
+        }
+        this.value = value;
+    }
+
+    /**
+     * Returns the string representation of this RunId.
+     *
+     * @return the unique identifier value
+     */
+    public String value() {
+        return value;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        RunId runId = (RunId) o;
+        return Objects.equals(value, runId.value);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(value);
+    }
+
+    @Override
+    public String toString() {
+        return value;
+    }
+}

pdf-umbenenner-domain/src/main/java/de/gecheckt/pdf/umbenenner/domain/model/package-info.java

@@ -0,0 +1,18 @@
+/**
+ * Domain model package containing core value objects and enumerations.
+ * <p>
+ * This package contains the fundamental domain entities and status models required for document processing:
+ * <ul>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.domain.model.ProcessingStatus} — enumeration of all valid document processing states</li>
+ * </ul>
+ * <p>
+ * All classes in this package are:
+ * <ul>
+ *   <li>Infrastructure-agnostic (no database, filesystem, network, or framework dependencies)</li>
+ *   <li>Immutable value objects or enumerations</li>
+ *   <li>Reusable across all layers via the Application and Adapter contracts</li>
+ * </ul>
+ *
+ * @since M2-AP-001
+ */
+package de.gecheckt.pdf.umbenenner.domain.model;

pdf-umbenenner-domain/src/main/java/de/gecheckt/pdf/umbenenner/domain/package-info.java

@@ -1,7 +1,18 @@
 /**
  * Domain layer containing business entities and value objects.
  * <p>
- * This package is infrastructure-agnostic and contains no dependencies on external systems.
+ * This package is infrastructure-agnostic and contains no dependencies on external systems,
- * AP-003: Currently empty as no domain logic has been implemented yet.
+ * databases, filesystems, HTTP clients, or any other technical infrastructure.
+ * <p>
+ * M2-AP-001 Implementation:
+ * <ul>
+ *   <li>{@link de.gecheckt.pdf.umbenenner.domain.model} — Core domain model including
+ *       {@link de.gecheckt.pdf.umbenenner.domain.model.ProcessingStatus} enumeration</li>
+ * </ul>
+ * <p>
+ * Subpackages:
+ * <ul>
+ *   <li><strong>model:</strong> Domain entities and value objects (e.g., status enumerations)</li>
+ * </ul>
  */
 package de.gecheckt.pdf.umbenenner.domain;

pdf-umbenenner-domain/src/test/java/de/gecheckt/pdf/umbenenner/domain/model/BatchRunContextTest.java

@@ -0,0 +1,175 @@
+package de.gecheckt.pdf.umbenenner.domain.model;
+
+import org.junit.jupiter.api.Test;
+
+import java.time.Instant;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Unit tests for {@link BatchRunContext}.
+ * <p>
+ * Verifies correct modeling of batch run lifecycle including initialization,
+ * timestamp tracking, completion marking, and state validation.
+ */
+class BatchRunContextTest {
+
+    @Test
+    void constructor_createsContextWithRunIdAndStartTime() {
+        RunId runId = new RunId("test-run");
+        Instant startTime = Instant.now();
+
+        BatchRunContext context = new BatchRunContext(runId, startTime);
+
+        assertNotNull(context);
+        assertEquals(runId, context.runId());
+        assertEquals(startTime, context.startInstant());
+    }
+
+    @Test
+    void constructor_throwsNullPointerExceptionWhenRunIdIsNull() {
+        Instant startTime = Instant.now();
+        assertThrows(NullPointerException.class, () -> new BatchRunContext(null, startTime),
+                "Constructor should throw NullPointerException when RunId is null");
+    }
+
+    @Test
+    void constructor_throwsNullPointerExceptionWhenStartInstantIsNull() {
+        RunId runId = new RunId("test-run");
+        assertThrows(NullPointerException.class, () -> new BatchRunContext(runId, null),
+                "Constructor should throw NullPointerException when start instant is null");
+    }
+
+    @Test
+    void runId_returnsTheConstructorRunId() {
+        RunId expectedRunId = new RunId("run-123");
+        Instant startTime = Instant.now();
+        BatchRunContext context = new BatchRunContext(expectedRunId, startTime);
+
+        assertEquals(expectedRunId, context.runId());
+    }
+
+    @Test
+    void startInstant_returnsTheConstructorStartTime() {
+        RunId runId = new RunId("test-run");
+        Instant expectedStartTime = Instant.parse("2026-03-31T20:00:00Z");
+        BatchRunContext context = new BatchRunContext(runId, expectedStartTime);
+
+        assertEquals(expectedStartTime, context.startInstant());
+    }
+
+    @Test
+    void endInstant_isNullImmediatelyAfterConstruction() {
+        RunId runId = new RunId("test-run");
+        Instant startTime = Instant.now();
+        BatchRunContext context = new BatchRunContext(runId, startTime);
+
+        assertNull(context.endInstant(), "End instant should be null immediately after construction");
+    }
+
+    @Test
+    void isCompleted_returnsFalseWhenEndInstantNotSet() {
+        RunId runId = new RunId("test-run");
+        Instant startTime = Instant.now();
+        BatchRunContext context = new BatchRunContext(runId, startTime);
+
+        assertFalse(context.isCompleted(), "isCompleted should return false when end instant is not set");
+    }
+
+    @Test
+    void setEndInstant_setsTheEndTime() {
+        RunId runId = new RunId("test-run");
+        Instant startTime = Instant.parse("2026-03-31T20:00:00Z");
+        Instant endTime = Instant.parse("2026-03-31T20:01:00Z");
+
+        BatchRunContext context = new BatchRunContext(runId, startTime);
+        context.setEndInstant(endTime);
+
+        assertEquals(endTime, context.endInstant());
+    }
+
+    @Test
+    void setEndInstant_throwsNullPointerExceptionWhenEndInstantIsNull() {
+        RunId runId = new RunId("test-run");
+        Instant startTime = Instant.now();
+        BatchRunContext context = new BatchRunContext(runId, startTime);
+
+        assertThrows(NullPointerException.class, () -> context.setEndInstant(null),
+                "setEndInstant should throw NullPointerException when end instant is null");
+    }
+
+    @Test
+    void setEndInstant_throwsIllegalStateExceptionWhenAlreadySet() {
+        RunId runId = new RunId("test-run");
+        Instant startTime = Instant.now();
+        Instant firstEndTime = Instant.now().plusSeconds(60);
+        Instant secondEndTime = Instant.now().plusSeconds(120);
+
+        BatchRunContext context = new BatchRunContext(runId, startTime);
+        context.setEndInstant(firstEndTime);
+
+        assertThrows(IllegalStateException.class, () -> context.setEndInstant(secondEndTime),
+                "setEndInstant should throw IllegalStateException when called a second time");
+    }
+
+    @Test
+    void isCompleted_returnsTrueAfterSetEndInstant() {
+        RunId runId = new RunId("test-run");
+        Instant startTime = Instant.now();
+        Instant endTime = Instant.now().plusSeconds(60);
+
+        BatchRunContext context = new BatchRunContext(runId, startTime);
+        context.setEndInstant(endTime);
+
+        assertTrue(context.isCompleted(), "isCompleted should return true after setting end instant");
+    }
+
+    @Test
+    void toString_containsRunIdAndTimestamps() {
+        RunId runId = new RunId("test-run-001");
+        Instant startTime = Instant.parse("2026-03-31T20:00:00Z");
+
+        BatchRunContext context = new BatchRunContext(runId, startTime);
+        String representation = context.toString();
+
+        assertTrue(representation.contains("test-run-001"), "toString should contain RunId");
+        assertTrue(representation.contains("2026-03-31"), "toString should contain timestamp information");
+    }
+
+    @Test
+    void contextLifecycle_startToCompletion() {
+        RunId runId = new RunId("test-run-lifecycle");
+        Instant startTime = Instant.parse("2026-03-31T20:00:00Z");
+        Instant endTime = Instant.parse("2026-03-31T20:05:00Z");
+
+        // Create context
+        BatchRunContext context = new BatchRunContext(runId, startTime);
+        assertFalse(context.isCompleted());
+
+        // Complete context
+        context.setEndInstant(endTime);
+        assertTrue(context.isCompleted());
+
+        // Verify all data
+        assertEquals(runId, context.runId());
+        assertEquals(startTime, context.startInstant());
+        assertEquals(endTime, context.endInstant());
+    }
+
+    @Test
+    void multipleContextsAreIndependent() {
+        RunId runId1 = new RunId("run-1");
+        RunId runId2 = new RunId("run-2");
+        Instant startTime1 = Instant.parse("2026-03-31T20:00:00Z");
+        Instant startTime2 = Instant.parse("2026-03-31T21:00:00Z");
+
+        BatchRunContext context1 = new BatchRunContext(runId1, startTime1);
+        BatchRunContext context2 = new BatchRunContext(runId2, startTime2);
+
+        Instant endTime1 = Instant.parse("2026-03-31T20:05:00Z");
+        context1.setEndInstant(endTime1);
+
+        assertTrue(context1.isCompleted());
+        assertFalse(context2.isCompleted(), "Context2 should not be affected by Context1's completion");
+    }
+}

pdf-umbenenner-domain/src/test/java/de/gecheckt/pdf/umbenenner/domain/model/ProcessingStatusTest.java

@@ -0,0 +1,91 @@
+package de.gecheckt.pdf.umbenenner.domain.model;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Unit tests for {@link ProcessingStatus} enumeration.
+ * <p>
+ * Verifies that all required status values are present and correctly defined
+ * for M2 and future milestones.
+ */
+class ProcessingStatusTest {
+
+    @Test
+    void allRequiredStatusValuesExist() {
+        // Verify all status values required by the architecture are present
+        assertNotNull(ProcessingStatus.SUCCESS);
+        assertNotNull(ProcessingStatus.FAILED_RETRYABLE);
+        assertNotNull(ProcessingStatus.FAILED_FINAL);
+        assertNotNull(ProcessingStatus.SKIPPED_ALREADY_PROCESSED);
+        assertNotNull(ProcessingStatus.SKIPPED_FINAL_FAILURE);
+        assertNotNull(ProcessingStatus.PROCESSING);
+    }
+
+    @Test
+    void successStatus_isDefinedAndAccessible() {
+        ProcessingStatus status = ProcessingStatus.SUCCESS;
+        assertEquals(ProcessingStatus.SUCCESS, status);
+    }
+
+    @Test
+    void failedRetryableStatus_isDefinedAndAccessible() {
+        ProcessingStatus status = ProcessingStatus.FAILED_RETRYABLE;
+        assertEquals(ProcessingStatus.FAILED_RETRYABLE, status);
+    }
+
+    @Test
+    void failedFinalStatus_isDefinedAndAccessible() {
+        ProcessingStatus status = ProcessingStatus.FAILED_FINAL;
+        assertEquals(ProcessingStatus.FAILED_FINAL, status);
+    }
+
+    @Test
+    void skippedAlreadyProcessedStatus_isDefinedAndAccessible() {
+        ProcessingStatus status = ProcessingStatus.SKIPPED_ALREADY_PROCESSED;
+        assertEquals(ProcessingStatus.SKIPPED_ALREADY_PROCESSED, status);
+    }
+
+    @Test
+    void skippedFinalFailureStatus_isDefinedAndAccessible() {
+        ProcessingStatus status = ProcessingStatus.SKIPPED_FINAL_FAILURE;
+        assertEquals(ProcessingStatus.SKIPPED_FINAL_FAILURE, status);
+    }
+
+    @Test
+    void processingStatus_isDefinedAndAccessible() {
+        ProcessingStatus status = ProcessingStatus.PROCESSING;
+        assertEquals(ProcessingStatus.PROCESSING, status);
+    }
+
+    @Test
+    void statusEquality_worksByReference() {
+        // Enums have identity-based equality
+        assertTrue(ProcessingStatus.SUCCESS == ProcessingStatus.SUCCESS);
+        assertFalse(ProcessingStatus.SUCCESS == ProcessingStatus.FAILED_FINAL);
+    }
+
+    @Test
+    void statusCanBeUsedInSwitch() {
+        ProcessingStatus status = ProcessingStatus.FAILED_RETRYABLE;
+        String result = "";
+
+        switch (status) {
+            case SUCCESS -> result = "success";
+            case FAILED_RETRYABLE -> result = "retryable";
+            case FAILED_FINAL -> result = "final";
+            case SKIPPED_ALREADY_PROCESSED -> result = "skip-processed";
+            case SKIPPED_FINAL_FAILURE -> result = "skip-failed";
+            case PROCESSING -> result = "processing";
+        }
+
+        assertEquals("retryable", result);
+    }
+
+    @Test
+    void statusValues_areSixInTotal() {
+        ProcessingStatus[] values = ProcessingStatus.values();
+        assertEquals(6, values.length, "ProcessingStatus should have exactly 6 values");
+    }
+}

pdf-umbenenner-domain/src/test/java/de/gecheckt/pdf/umbenenner/domain/model/RunIdTest.java

@@ -0,0 +1,146 @@
+package de.gecheckt.pdf.umbenenner.domain.model;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Unit tests for {@link RunId} value object.
+ * <p>
+ * Verifies immutability, value semantics, validation, and correct behavior
+ * as a unique identifier for batch runs.
+ */
+class RunIdTest {
+
+    @Test
+    void constructor_createsRunIdWithValidValue() {
+        RunId runId = new RunId("test-run-123");
+        assertNotNull(runId);
+        assertEquals("test-run-123", runId.value());
+    }
+
+    @Test
+    void constructor_throwsNullPointerExceptionWhenValueIsNull() {
+        assertThrows(NullPointerException.class, () -> new RunId(null),
+                "Constructor should throw NullPointerException for null value");
+    }
+
+    @Test
+    void constructor_throwsIllegalArgumentExceptionWhenValueIsEmpty() {
+        assertThrows(IllegalArgumentException.class, () -> new RunId(""),
+                "Constructor should throw IllegalArgumentException for empty value");
+    }
+
+    @Test
+    void constructor_throwsIllegalArgumentExceptionWhenValueIsOnlyWhitespace() {
+        assertThrows(IllegalArgumentException.class, () -> new RunId("   "),
+                "Constructor should throw IllegalArgumentException for whitespace-only value");
+    }
+
+    @Test
+    void value_returnsTheConstructorValue() {
+        String expectedValue = "run-id-456";
+        RunId runId = new RunId(expectedValue);
+        assertEquals(expectedValue, runId.value());
+    }
+
+    @Test
+    void equals_returnsTrueForIdenticalValues() {
+        RunId runId1 = new RunId("same-id");
+        RunId runId2 = new RunId("same-id");
+        assertEquals(runId1, runId2);
+    }
+
+    @Test
+    void equals_returnsFalseForDifferentValues() {
+        RunId runId1 = new RunId("id-1");
+        RunId runId2 = new RunId("id-2");
+        assertNotEquals(runId1, runId2);
+    }
+
+    @Test
+    void equals_returnsFalseWhenComparedWithNull() {
+        RunId runId = new RunId("test-id");
+        assertNotEquals(runId, null);
+        assertFalse(runId.equals(null));
+    }
+
+    @Test
+    void equals_returnsFalseWhenComparedWithDifferentType() {
+        RunId runId = new RunId("test-id");
+        assertNotEquals(runId, "test-id");
+        assertFalse(runId.equals("test-id"));
+    }
+
+    @Test
+    void hashCode_isSameForIdenticalValues() {
+        RunId runId1 = new RunId("same-id");
+        RunId runId2 = new RunId("same-id");
+        assertEquals(runId1.hashCode(), runId2.hashCode());
+    }
+
+    @Test
+    void hashCode_isDifferentForDifferentValues() {
+        RunId runId1 = new RunId("id-1");
+        RunId runId2 = new RunId("id-2");
+        // Note: this is not guaranteed for different values, but likely
+        assertNotEquals(runId1.hashCode(), runId2.hashCode());
+    }
+
+    @Test
+    void toString_returnsTheValue() {
+        String value = "run-id-789";
+        RunId runId = new RunId(value);
+        assertEquals(value, runId.toString());
+    }
+
+    @Test
+    void runIdCanBeUsedInCollections() {
+        RunId runId1 = new RunId("id-1");
+        RunId runId2 = new RunId("id-1");
+        RunId runId3 = new RunId("id-2");
+
+        var set = new java.util.HashSet<RunId>();
+        set.add(runId1);
+        set.add(runId2); // Should not add duplicate
+        set.add(runId3);
+
+        // runId1 and runId2 are equal, so set should have 2 elements
+        assertEquals(2, set.size());
+    }
+
+    @Test
+    void runIdCanBeMapKey() {
+        RunId runId1 = new RunId("id-1");
+        RunId runId2 = new RunId("id-1");
+
+        var map = new java.util.HashMap<RunId, String>();
+        map.put(runId1, "first");
+        map.put(runId2, "second");
+
+        // runId1 and runId2 are equal, so second put should overwrite
+        assertEquals(1, map.size());
+        assertEquals("second", map.get(runId1));
+    }
+
+    @Test
+    void constructor_acceptsUuidFormatValue() {
+        String uuidValue = "550e8400-e29b-41d4-a716-446655440000";
+        RunId runId = new RunId(uuidValue);
+        assertEquals(uuidValue, runId.value());
+    }
+
+    @Test
+    void constructor_acceptsTimestampFormatValue() {
+        String timestampValue = "2026-03-31T21:41:48.000Z";
+        RunId runId = new RunId(timestampValue);
+        assertEquals(timestampValue, runId.value());
+    }
+
+    @Test
+    void constructor_acceptsSequentialNumberValue() {
+        String sequentialValue = "00001";
+        RunId runId = new RunId(sequentialValue);
+        assertEquals(sequentialValue, runId.value());
+    }
+}