feat: bindmount userscript and point Violentmonkey at the backend

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docker-compose.yml

@@ -20,6 +20,8 @@ services:
       PORT: "8080"
       # Gates the browser UI. Unset means the web routes are not served at all.
       WEB_PASSWORD: ${WEB_PASSWORD:-}
+      # Path inside the container; matches the bindmount above.
+      USERSCRIPT_PATH: ${USERSCRIPT_PATH:-/userscript/manga-bookmark.user.js}
       # Latest-chapter poller. LATEST_CHAPTER_POLL_ENABLED=0 in .env is the kill
       # switch; it only takes effect because these are listed here.
       LATEST_CHAPTER_POLL_ENABLED: ${LATEST_CHAPTER_POLL_ENABLED:-1}
@@ -29,6 +31,11 @@ services:
       LATEST_CHAPTER_POLL_STAGGER: ${LATEST_CHAPTER_POLL_STAGGER:-20s}
     volumes:
       - bookmarks-data:/data
+      # The userscript is served from here, read fresh on every request. Editing
+      # the file in this checkout takes effect on the next Violentmonkey poll —
+      # no rebuild, no restart. `git pull` restores the committed version, which
+      # is why a redeploy always ships the repo's script.
+      - ./userscript:/userscript:ro
     # Bound to loopback only: the proxy (or curl during smoke test) reaches it,
     # the public internet does not.
     ports: