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>

docker-compose.yaml

@@ -13,8 +13,9 @@ services:
       POLL_INTERVAL: "300"
       MEDIA_EXTENSIONS: ".mp4,.mkv,.avi,.wmv,.mov,.webm,.flv,.m4v"
       HASH_ALGORITHM: "sha256"
-      MOVE_MODE: "move"
-      LOG_LEVEL: "INFO"
+      MOVE_MODE: "copy"
+      QBIT_CATEGORY: "Stash"
+      LOG_LEVEL: "DEBUG"
     volumes:
       - /data/staging:/staging:ro
       - /data/stash-import:/import