feat: add Agrarmonitor integration module

- New backend module (agrarmonitor) with status check and device registration
- Frontend settings tab with connection status display and registration form
- Environment variables for base URLs, credentials, cookie path and encryption key
- Docker Compose env passthrough for agrarmonitor config

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

paperless-backend/package.json

@@ -31,6 +31,7 @@
     "@types/form-data": "^2.2.1",
     "@types/passport-jwt": "^4.0.1",
     "@types/uuid": "^10.0.0",
+    "agrarmonitor-connector": "git+https://gitea.poettker-cloud.de/bjoernpoettker/AgrarmonitorConnector.git",
     "axios": "^1.14.0",
     "basic-ftp": "^5.2.1",
     "chokidar": "^4.0.3",