feat: интеграция с VPS Tracker

Исходящий sync bindings после updateConfig, настройки в app_settings, страница Интеграции, приём событий vps_down для DNS failover.

Co-authored-by: Cursor <[email protected]>

packages/db/migrations/013_app_settings.sql

@@ -0,0 +1,13 @@
+-- Application settings (single row)
+CREATE TABLE IF NOT EXISTS app_settings (
+  id TEXT PRIMARY KEY,
+  app_switcher_json TEXT,
+  vps_tracker_url TEXT,
+  vps_tracker_integration_token TEXT,
+  vps_tracker_sync_enabled INTEGER NOT NULL DEFAULT 0,
+  vps_tracker_last_sync_at TEXT,
+  created_at TEXT NOT NULL DEFAULT (datetime('now')),
+  updated_at TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+INSERT OR IGNORE INTO app_settings (id) VALUES ('settings-main');