admin/skills: fail loud on DB error + read skills dir from env

- Raise HTTPException(503) when Paperclip DB is unreachable instead of
  silently falling through to disk-only mode and returning [].
- Honor PAPERCLIP_SKILLS_DIR env var (falls back to ~/.paperclip/...).
  In the Coolify container the host's skills dir is bind-mounted at
  /paperclip-skills; without this, Path.home() resolved to /root/ and
  the disk inventory was always empty.

Both bugs together silently turned a Paperclip DB outage into "no skills
installed" on the /skills page.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/app.py

@@ -2656,9 +2656,15 @@ async def api_reset_methodology(category: str, key: str):
 PAPERCLIP_DB_URL = os.environ.get(
     "PAPERCLIP_DB_URL", "postgresql://paperclip:paperclip@127.0.0.1:54329/paperclip"
 )
-# Paperclip runs locally via pm2; skills are in ~/.paperclip
-_local_skills = Path.home() / ".paperclip" / "instances" / "default" / "skills"
-PAPERCLIP_SKILLS_DIR = _local_skills
+# Paperclip skills directory. In the Coolify container this is bind-mounted from
+# the host's ~/.paperclip/instances/default/skills (see PAPERCLIP_SKILLS_DIR env).
+# Fallback to the host path for local/dev use.
+PAPERCLIP_SKILLS_DIR = Path(
+    os.environ.get(
+        "PAPERCLIP_SKILLS_DIR",
+        str(Path.home() / ".paperclip" / "instances" / "default" / "skills"),
+    )
+)
 # Default company ID for skills
 SKILLS_COMPANY_ID = os.environ.get("PAPERCLIP_COMPANY_ID", "42a7acd0-30c5-4cbd-ac97-7424f65df294")
 
@@ -2666,7 +2672,6 @@ SKILLS_COMPANY_ID = os.environ.get("PAPERCLIP_COMPANY_ID", "42a7acd0-30c5-4cbd-a
 @app.get("/api/admin/skills")
 async def api_list_skills():
     """List installed Paperclip skills with DB sync status."""
-    rows = []
     try:
         conn = await asyncpg.connect(PAPERCLIP_DB_URL, timeout=5)
         try:
@@ -2677,9 +2682,12 @@ async def api_list_skills():
             )
         finally:
             await conn.close()
-    except (OSError, asyncpg.PostgresError, asyncpg.InterfaceError, TimeoutError):
-        # Paperclip DB unreachable — continue with disk-only skills
-        pass
+    except (OSError, asyncpg.PostgresError, asyncpg.InterfaceError, TimeoutError) as e:
+        logger.exception("Paperclip DB unreachable while listing skills")
+        raise HTTPException(
+            status_code=503,
+            detail=f"Paperclip database unreachable: {type(e).__name__}: {e}",
+        ) from e
 
     skills = []
     for r in rows: