Wire the consume folder to a user-reachable source

[helix-a]

Paperless watches a consume/ folder, but nothing puts a user within reach of it — startos/dependencies.ts declares none, so documents can only arrive through the web UI.

Fix: an optional File Browser dependency mounted read-only into the consume path, with a config action to toggle it. jellyfin-startos and audiobookshelf-startos already implement this pattern.

[7thgenerationdesign]

@helix-nine , I (and I think others) would really appreciate if a Nextcloud directory could also be mounted read-only for the consume path, as I mentioned in my request #3

[helix-a]

Implemented in #9, with one change from the proposal: the mount is read-write, not read-only. Paperless deletes the source file after a successful import, and it does so inside the same database transaction that stores the document (consumer.py, ConsumerPlugin.run), so on a read-only mount every import would fail and roll back. Read-write is also what the qbittorrent and metube packages already do with FileBrowser Quantum's volume, and Paperless already runs as uid 1000 — the same uid FileBrowser Quantum serves its files as — so nothing else is needed.

Set Consume Folder action → choose FileBrowser Quantum and a subfolder (default paperless). Anything dropped there is imported and then removed.

@7thgenerationdesign — re Nextcloud: rather than mounting Nextcloud's data directory directly (which would need your Nextcloud username to reach data/<user>/files/…, and Nextcloud's primary storage doesn't notice files deleted out from under it, so every consumed document would linger as a ghost entry), the Nextcloud package already mounts FileBrowser Quantum's volume as Local external storage and rescans it on access. So with both installed, the same folder is visible inside Nextcloud: drop a file into it from Nextcloud (web, desktop sync, mobile), Paperless imports it, and it disappears from Nextcloud as well. Details on #3.