feat(trackers): user filters for Gitea, webhook polling cleanup, dashboard navigability

- Gitea: NotificationTracker now exposes sender allowlist / blocklist filters
  via MultiEntitySelect, populated from Gitea /users/search merged with past
  EventLog senders so the picker is useful before the first webhook arrives.
- Webhook providers (gitea, planka, webhook): stop scheduling interval polling
  jobs on tracker create/update/startup; hide the "every Xs" indicator in the
  tracker list since there is no polling.
- Dashboard: stat cards are now <a> links that route to providers, trackers,
  targets, command-trackers, or scroll to the events panel. Provider deck
  rows highlight the target provider on click.
- Command trackers / command configs: auto-reselect the right config when the
  provider type changes (matches notification-tracker behavior).
- Migration: drop legacy batch_duration column from notification_tracker —
  the field is gone from the model but its NOT NULL constraint blocked
  inserts on older DBs.
- Docs: refresh entity-relationships.md with current NotificationTracker
  fields (filters, adaptive_max_skip, default_*_config_id).

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

@@ -197,6 +197,21 @@ async def migrate_schema(engine: AsyncEngine) -> None:
                 )
                 logger.info("Added filters column to %s table", tracker_table)
 
+        # Drop legacy batch_duration column from notification_tracker.
+        # The field was removed from the SQLModel class but the column still
+        # exists as NOT NULL in older DBs, so INSERTs from the new code fail
+        # with "NOT NULL constraint failed: notification_tracker.batch_duration".
+        if await _has_table(conn, tracker_table):
+            if await _has_column(conn, tracker_table, "batch_duration"):
+                _assert_ident(tracker_table, "table")
+                await conn.execute(
+                    text(f"ALTER TABLE {tracker_table} DROP COLUMN batch_duration")
+                )
+                logger.info(
+                    "Dropped legacy batch_duration column from %s table",
+                    tracker_table,
+                )
+
         # Add Gitea tracking flags to tracking_config if missing
         if await _has_table(conn, "tracking_config"):
             gitea_flags = [