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).

frontend/src/lib/i18n/en.json

@@ -246,6 +246,9 @@
 		"selectAlbums": "Select albums...",
 		"repositories": "Repositories",
 		"selectRepositories": "Select repositories...",
+		"userAllowlist": "Only from users",
+		"userBlocklist": "Exclude users",
+		"selectUsers": "Pick users...",
 		"boards": "Boards",
 		"selectBoards": "Select boards...",
 		"upsDevices": "UPS Devices",

frontend/src/lib/i18n/ru.json

@@ -246,6 +246,9 @@
 		"selectAlbums": "Выберите альбомы...",
 		"repositories": "Репозитории",
 		"selectRepositories": "Выберите репозитории...",
+		"userAllowlist": "Только от пользователей",
+		"userBlocklist": "Исключить пользователей",
+		"selectUsers": "Выберите пользователей...",
 		"boards": "Доски",
 		"selectBoards": "Выберите доски...",
 		"upsDevices": "ИБП устройства",