feat: add Gitea as webhook-based service provider

First webhook-based provider integration (Immich uses polling).
Gitea pushes events via POST /api/webhooks/gitea/{provider_id} with
HMAC-SHA256 signature validation.

- 9 event types: push, issue opened/closed/commented, PR opened/closed/merged/commented, release published
- Generic filters system on NotificationTracker (collections, senders, exclude_senders)
- Provider capabilities include supported_filters and webhook_based flag
- Gitea API client for connection testing and repository listing
- 18 default Jinja2 notification templates (EN + RU)
- Frontend: conditional provider forms, Gitea event toggles in tracking config
- Auto-migration for filters column and Gitea tracking flags

packages/server/src/notify_bridge_server/database/models.py

@@ -115,6 +115,19 @@ class TrackingConfig(SQLModel, table=True):
     track_collection_renamed: bool = Field(default=True)
     track_collection_deleted: bool = Field(default=True)
     track_sharing_changed: bool = Field(default=False)
+
+    # Gitea event tracking
+    track_push: bool = Field(default=True)
+    track_issue_opened: bool = Field(default=True)
+    track_issue_closed: bool = Field(default=True)
+    track_issue_commented: bool = Field(default=False)
+    track_pr_opened: bool = Field(default=True)
+    track_pr_closed: bool = Field(default=True)
+    track_pr_merged: bool = Field(default=True)
+    track_pr_commented: bool = Field(default=False)
+    track_release_published: bool = Field(default=True)
+
+    # Immich asset display
     track_images: bool = Field(default=True)
     track_videos: bool = Field(default=True)
     notify_favorites_only: bool = Field(default=False)
@@ -247,6 +260,7 @@ class NotificationTracker(SQLModel, table=True):
     name: str
     icon: str = Field(default="")
     collection_ids: list[str] = Field(default_factory=list, sa_column=Column(JSON))
+    filters: dict[str, Any] = Field(default_factory=dict, sa_column=Column(JSON))
     scan_interval: int = Field(default=60)
     batch_duration: int = Field(default=0)  # seconds to accumulate events before dispatch (0=immediate)
     enabled: bool = Field(default=True)