feat: add Scheduler provider + multi-provider UX fixes

Scheduler provider:
- Virtual provider (no external service) that emits SCHEDULED_MESSAGE
  events on user-defined intervals or cron expressions
- Custom variables stored in tracker filters, flattened into template context
- fire_count persists across triggers via tracker state
- APScheduler CronTrigger support for cron-mode schedules
- Default templates (EN+RU), seeded on startup

Multi-provider UX fixes:
- Tracking config hides Immich-specific sections (periodic, scheduled,
  memory, asset display) for non-Immich providers
- Command config driven by provider capabilities — hides commands/settings
  for providers without bot commands
- Template config hides empty "Scheduled Messages" group
- Test menu on tracker targets is provider-aware (Immich shows all 4 test
  types, others show only basic)
- Removed redundant Test button from tracker card
- System-owned tracking configs (user_id=0) seeded for Gitea + Scheduler
- Fixed ownership checks to allow system configs in tracker-target links
- Capabilities cache shared across template-configs and command-configs
- Command tracker bot selector uses EntitySelect instead of raw select
- Sample context includes Gitea + Scheduler variables for template preview

packages/server/src/notify_bridge_server/api/notification_tracker_targets.py

@@ -94,7 +94,7 @@ async def create_notification_tracker_target(
     # Validate config ownership + provider type match
     if body.tracking_config_id:
         tc = await session.get(TrackingConfig, body.tracking_config_id)
-        if not tc or tc.user_id != user.id:
+        if not tc or (tc.user_id != user.id and tc.user_id != 0):
             raise HTTPException(status_code=404, detail="Tracking config not found")
         if tc.provider_type != provider.type:
             raise HTTPException(
@@ -139,7 +139,7 @@ async def update_notification_tracker_target(
     # Validate config ownership + provider type match if being changed
     if "tracking_config_id" in updates and updates["tracking_config_id"]:
         tc = await session.get(TrackingConfig, updates["tracking_config_id"])
-        if not tc or tc.user_id != user.id:
+        if not tc or (tc.user_id != user.id and tc.user_id != 0):
             raise HTTPException(status_code=404, detail="Tracking config not found")
         if tc.provider_type != provider.type:
             raise HTTPException(

packages/server/src/notify_bridge_server/api/providers.py

@@ -97,6 +97,8 @@ async def create_provider(
                         detail=test_result.get("message", "Cannot connect to Gitea"),
                     )
 
+    # Scheduler: no validation needed (virtual provider)
+
     provider = ServiceProvider(
         user_id=user.id,
         type=body.type,
@@ -253,6 +255,9 @@ async def test_provider(
             gitea = make_gitea_provider(http_session, provider)
             return await gitea.test_connection()
 
+    if provider.type == "scheduler":
+        return {"ok": True, "message": "Virtual provider — always available"}
+
     return {"ok": False, "message": f"Unknown provider type: {provider.type}"}
 
 

packages/server/src/notify_bridge_server/api/tracking_configs.py

@@ -101,7 +101,10 @@ async def list_configs(
     user: User = Depends(get_current_user),
     session: AsyncSession = Depends(get_session),
 ):
-    query = select(TrackingConfig).where(TrackingConfig.user_id == user.id)
+    from sqlmodel import or_
+    query = select(TrackingConfig).where(
+        or_(TrackingConfig.user_id == user.id, TrackingConfig.user_id == 0)
+    )
     if provider_type:
         query = query.where(TrackingConfig.provider_type == provider_type)
     result = await session.exec(query)
@@ -167,6 +170,6 @@ def _response(c: TrackingConfig) -> dict:
 
 async def _get(session: AsyncSession, config_id: int, user_id: int) -> TrackingConfig:
     config = await session.get(TrackingConfig, config_id)
-    if not config or config.user_id != user_id:
+    if not config or (config.user_id != user_id and config.user_id != 0):
         raise HTTPException(status_code=404, detail="Tracking config not found")
     return config

packages/server/src/notify_bridge_server/api/webhooks.py

@@ -277,6 +277,8 @@ def _event_allowed_by_tracking_config(event: ServiceEvent, tc: TrackingConfig) -
         "pr_merged": tc.track_pr_merged,
         "pr_commented": tc.track_pr_commented,
         "release_published": tc.track_release_published,
+        # Scheduler events
+        "scheduled_message": tc.track_scheduled_message,
         # Immich events
         "assets_added": tc.track_assets_added,
         "assets_removed": tc.track_assets_removed,