Add category filtering, default to copy mode, split dev/prod compose

- Default MOVE_MODE changed to copy so qBit can continue seeding
- Add QBIT_CATEGORY env var (default "Stash") to filter torrents
- Split compose into dev (build from source) and prod (pre-built image)
- Fix Dockerfile COPY glob needing trailing slash
- Update README and summary docs

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

qbit_client.py

@@ -37,9 +37,12 @@ class QBitClient:
         resp.raise_for_status()
         return resp
 
-    def get_completed_torrents(self):
+    def get_completed_torrents(self, category=None):
         """Return a list of completed torrent dicts from qBittorrent."""
-        resp = self._request("GET", "/api/v2/torrents/info", params={"filter": "completed"})
+        params = {"filter": "completed"}
+        if category:
+            params["category"] = category
+        resp = self._request("GET", "/api/v2/torrents/info", params=params)
         return resp.json()
 
     def get_torrent_files(self, info_hash):