Add pull_image + list_registries; remove Gruppe 5 (no Volume API)

- pull_image: SYNO.Docker.Image/pull with repository+tag split via
  rpartition; polls image list every 3 s until image appears, 120 s timeout
- list_registries: SYNO.Docker.Registry/get; shows name, URL, active marker
- Gruppe 5 (Volumes) removed from roadmap — SYNO.Docker.Volume does not exist
- CLAUDE.md: tool count 17 → 19, Volumes section removed
- 28 tests all passing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/mcp_synology_container/modules/images.py

@@ -1,7 +1,8 @@
-"""MCP tools for SYNO.Docker.Image: list, check updates, delete."""
+"""MCP tools for SYNO.Docker.Image: list, check updates, delete, pull."""
 
 from __future__ import annotations
 
+import asyncio
 import json
 import logging
 import sys
@@ -269,6 +270,56 @@ def register_images(mcp: FastMCP, config: AppConfig, client: DsmClient) -> None:
 
         return f"Deleted {display_name} — {size_str} freed."
 
+    @mcp.tool()
+    async def pull_image(image: str) -> str:
+        """Pull a Docker image from the active registry.
+
+        Splits the image reference into repository and tag, triggers the pull
+        via DSM, then polls the image list until the image appears (up to 120 s).
+
+        Args:
+            image: Image reference as "name:tag" (e.g. "postgres:17.8").
+                   Tag defaults to "latest" when omitted.
+        """
+        repository, sep, tag = image.rpartition(":")
+        if not sep:
+            repository = image
+            tag = "latest"
+
+        try:
+            await client.request(
+                "SYNO.Docker.Image",
+                "pull",
+                params={"repository": repository, "tag": tag},
+            )
+        except Exception as e:
+            return f"Error starting pull of '{image}': {e}"
+
+        # DSM starts the pull asynchronously; poll until the image appears.
+        deadline = 120
+        interval = 3
+        elapsed = 0
+        while elapsed < deadline:
+            await asyncio.sleep(interval)
+            elapsed += interval
+            try:
+                img_data = await client.request(
+                    "SYNO.Docker.Image",
+                    "list",
+                    params={"limit": "-1", "offset": "0", "show_dsm": "false"},
+                )
+            except Exception:
+                continue
+            for img in img_data.get("images", []):
+                if img.get("repository") == repository and tag in (img.get("tags") or []):
+                    size_str = _human_size(img.get("size", 0))
+                    return f"Pulled {repository}:{tag} — {size_str}."
+
+        return (
+            f"Pull of '{repository}:{tag}' started but did not complete within "
+            f"{deadline} s. Check DSM Container Manager for status."
+        )
+
     @mcp.tool()
     async def check_image_updates(project_name: str | None = None) -> str:
         """Check for available image updates for a project or all images.

src/mcp_synology_container/modules/registries.py

@@ -0,0 +1,49 @@
+"""MCP tools for SYNO.Docker.Registry: list."""
+
+from __future__ import annotations
+
+import logging
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from mcp.server.fastmcp import FastMCP
+
+    from mcp_synology_container.config import AppConfig
+    from mcp_synology_container.dsm_client import DsmClient
+
+logger = logging.getLogger(__name__)
+
+
+def register_registries(mcp: FastMCP, config: AppConfig, client: DsmClient) -> None:
+    """Register all registry management tools with the MCP server."""
+
+    @mcp.tool()
+    async def list_registries() -> str:
+        """List all configured Docker registries.
+
+        Shows name, URL, and marks the currently active registry.
+        Uses SYNO.Docker.Registry/get which returns the registries array
+        and the name of the currently active registry in the "using" field.
+        """
+        try:
+            data = await client.request("SYNO.Docker.Registry", "get")
+        except Exception as e:
+            return f"Error listing registries: {e}"
+
+        registries = data.get("registries", [])
+        using = data.get("using", "")
+
+        if not registries:
+            return "No registries configured."
+
+        lines = [f"Registries ({len(registries)} total):", ""]
+        for reg in registries:
+            name = reg.get("name", "?")
+            url = reg.get("url", "?")
+            active_marker = "  [active]" if name == using else ""
+            mirror_marker = "  [mirror enabled]" if reg.get("enable_registry_mirror") else ""
+            lines.append(f"  {name}{active_marker}")
+            lines.append(f"    URL: {url}{mirror_marker}")
+            lines.append("")
+
+        return "\n".join(lines).rstrip()

src/mcp_synology_container/server.py

@@ -31,6 +31,7 @@ def create_server(config: AppConfig, client: DsmClient) -> FastMCP:
     from mcp_synology_container.modules.images import register_images
     from mcp_synology_container.modules.networks import register_networks
     from mcp_synology_container.modules.projects import register_projects
+    from mcp_synology_container.modules.registries import register_registries
     from mcp_synology_container.modules.system import register_system
 
     register_projects(mcp, config, client)
@@ -39,6 +40,7 @@ def create_server(config: AppConfig, client: DsmClient) -> FastMCP:
     register_images(mcp, config, client)
     register_system(mcp, config, client)
     register_networks(mcp, config, client)
+    register_registries(mcp, config, client)
 
     logger.info("MCP server configured with all tool modules")
     return mcp