Adds two managed system overlays (l4d2center-maps, cedapug-maps) that
fetch curated map archives from upstream sources and reconcile addons
symlinks for non-Steam maps. A daily systemd timer enqueues a coalesced
refresh_global_overlays worker job; downloads, extraction, and rebuilds
run in the existing job worker and surface in the job log UI.
Schema: GlobalOverlaySource / GlobalOverlayItem / GlobalOverlayItemFile
plus nullable Job.user_id so system jobs render as "system" in the UI.
The new builder reconciles symlinks against the per-source vpk cache
and leaves foreign symlinks untouched. Initialize-time guard refuses
to mount a partial overlay if any expected vpk is missing from cache.
Refresh service uses shutil.move to handle EXDEV when /tmp and the
cache live on different filesystems.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds Overlay.type and Overlay.user_id with two partial unique indexes
(externals globally unique by name; user overlays unique per user).
Adds WorkshopItem registry keyed on steam_id and a pure many-to-many
overlay_workshop_items association. Adds Job.overlay_id for build_overlay
job tracking. Switches overlays.id to AUTOINCREMENT so deleted IDs are
never reused.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
