Fix compose path: strip /volumeN prefix for FileStation API

Container Manager returns raw filesystem paths (/volume1/docker/...),
but SYNO.FileStation.* APIs expect paths without the volume prefix
(/docker/...). Add _to_filestation_path() to strip /volumeN and apply
it in _find_compose_path before any FileStation call.

Also switch directory probe from getinfo (returns truthy files array
with embedded code:408 for missing paths) to list (empty files array
for non-existent directories), and apply the same prefix stripping to
the error message shown when no compose file is found.

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

src/mcp_synology_container/modules/compose.py

@@ -7,6 +7,8 @@ Supported filenames: docker-compose.yml, docker-compose.yaml, compose.yml, compo
 from __future__ import annotations
 
 import logging
+import re
+import sys
 from typing import TYPE_CHECKING, Any
 
 import yaml
@@ -20,6 +22,18 @@ from mcp_synology_container.modules.projects import _find_project
 
 logger = logging.getLogger(__name__)
 
+_VOLUME_PREFIX_RE = re.compile(r"^/volume\d+")
+
+
+def _to_filestation_path(path: str) -> str:
+    """Strip /volumeN prefix so paths work with the FileStation API.
+
+    The Docker/Container Manager API returns raw filesystem paths like
+    /volume1/docker/myapp, but FileStation expects /docker/myapp.
+    """
+    return _VOLUME_PREFIX_RE.sub("", path)
+
+
 # Recognized compose file names (in priority order)
 _COMPOSE_FILENAMES = [
     "docker-compose.yml",
@@ -45,11 +59,12 @@ def register_compose(mcp: FastMCP, config: AppConfig, client: DsmClient) -> None
         path = await _find_compose_path(client, config, project_name)
         if path is None:
             project = await _find_project(client, project_name)
-            searched = (
+            raw = (
                 project.get("path", f"{config.compose_base_path}/{project_name}")
                 if project
                 else f"{config.compose_base_path}/{project_name}"
             )
+            searched = _to_filestation_path(raw)
             return (
                 f"No compose file found for project '{project_name}'.\n"
                 f"Looked in {searched}/ for: " + ", ".join(_COMPOSE_FILENAMES)
@@ -326,18 +341,29 @@ async def _find_compose_path(
             base,
         )
 
-    for filename in _COMPOSE_FILENAMES:
+    # FileStation API requires paths without the /volumeN prefix.
-        path = f"{base}/{filename}"
+    fs_base = _to_filestation_path(base)
+
+    # List the directory once and match against known filenames.
+    # getinfo returns {"files": [{"code": 408, ...}]} for missing paths
+    # (truthy but erroneous), so listing the directory is more reliable.
     try:
         data = await client.request(
             "SYNO.FileStation.List",
-                "getinfo",
+            "list",
-                params={"path": path, "additional": "[]"},
+            params={"folder_path": fs_base, "additional": "[]"},
         )
-            if data.get("files"):
+        names_present = {f.get("name", "") for f in data.get("files", [])}
+        sys.stderr.write(f"[compose] files in {fs_base}: {sorted(names_present)}\n")
+        sys.stderr.flush()
+    except Exception as e:
+        logger.debug("Could not list directory '%s': %s", fs_base, e)
+        names_present = set()
+
+    for filename in _COMPOSE_FILENAMES:
+        if filename in names_present:
+            path = f"{fs_base}/{filename}"
             logger.debug("Found compose file: %s", path)
             return path
-        except Exception:
-            continue
 
     return None