Add hybrid app version labels

backend/README.md

@@ -71,7 +71,13 @@ SMTP_TIMEOUT=30
 
 # Jellyfin, Jellyseerr, and SSH targets are now configured per machine in the app's Settings tab.
 # The backend seeds a local machine automatically, so no global Jellyfin or SSH env vars are required.
-#
+
+# Versioning
+# The backend tries to auto-detect its version from installed package metadata.
+# If needed, you can override the displayed version/build markers with APP_VERSION and APP_BUILD_INFO.
+APP_VERSION=0.1.0
+APP_BUILD_INFO=dev
+
 # Authentik / OIDC
 AUTH_ENABLED=true
 OIDC_ISSUER_URL=https://authentik.example/application/o/media-library-viewer/
@@ -150,3 +156,4 @@ For local development, `docker compose -f docker-compose.dev.yml up --build` doe
 - `GET /api/jobs/templates` — Available jobs
 - `POST /api/jobs/run` — Execute a job
 - `GET /api/users` — Jellyfin users with optional Jellyseerr enrichment
+- `GET /api/version` — Backend version/build metadata for the UI