Fix Jenkins-update flow: redeploy_project pull + delete_image safety + delete_container

Bug fixes from product test:
1. redeploy_project: BUILD_FAILED now includes explicit image pull (stop → pull → start)
2. delete_image: Distinguishes running vs stopped containers, suggests system_prune for stopped refs
3. New tool delete_container: Verify stopped state before deletion, confirmation required

Tests added for all three paths plus stopped-container edge cases.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/mcp_synology_container/modules/containers.py

@@ -312,6 +312,58 @@ def register_containers(mcp: FastMCP, config: AppConfig, client: DsmClient) -> N
 
         return "\n".join(result_lines)
 
+    @mcp.tool()
+    async def delete_container(container_name: str, confirmed: bool = False) -> str:
+        """Delete a container.
+
+        Container must be stopped before deletion. Without confirmed=True,
+        returns a preview only.
+
+        Args:
+            container_name: Name of the container.
+            confirmed: Must be True to proceed. Set to True to confirm deletion.
+        """
+        if not confirmed:
+            return (
+                f"Preview: would delete container '{container_name}'.\n"
+                f"Call this tool again with confirmed=True to proceed."
+            )
+
+        resolved_name = await _resolve_container_name(client, container_name)
+        display_name = _strip_hash_prefix(resolved_name)
+
+        try:
+            data = await client.request(
+                "SYNO.Docker.Container",
+                "get",
+                params={"name": resolved_name},
+            )
+        except Exception as e:
+            return f"Error inspecting container '{container_name}': {e}"
+
+        if not data:
+            return f"Container '{container_name}' not found."
+
+        details = data.get("details", {}) or {}
+        state = details.get("State", {}) or {}
+        running = state.get("Running", False)
+
+        if running:
+            return (
+                f"Cannot delete '{display_name}': container is still running.\n"
+                f"Stop the container first with stop_project or stop_container."
+            )
+
+        try:
+            await client.request(
+                "SYNO.Docker.Container",
+                "delete",
+                params={"name": resolved_name},
+            )
+            return f"Deleted container '{display_name}'."
+        except Exception as e:
+            return f"Error deleting '{display_name}': {e}"
+
 
 def _container_in_project(container: dict[str, Any], project_name: str) -> bool:
     """Check if a container belongs to a project based on its labels."""
@@ -350,9 +402,7 @@ def _format_container_detail(name: str, data: dict[str, Any]) -> str:
         lines.append(f"  Exit code: {state.get('ExitCode', '?')}")
 
     # IP addresses from all attached networks
-    networks: dict[str, Any] = (
-        details.get("NetworkSettings", {}) or {}
-    ).get("Networks", {}) or {}
+    networks: dict[str, Any] = (details.get("NetworkSettings", {}) or {}).get("Networks", {}) or {}
     for net_name, net in networks.items():
         ip = (net or {}).get("IPAddress", "")
         if ip: