Use database fleet registry and gate RCON polling on container readiness

src/lib/server/db/index.ts

@@ -12,6 +12,7 @@ let _db: Database.Database | null = null;
 // IF NOT EXISTS in schema.sql is a no-op on existing tables, so it can't
 // backfill columns; this can.
 const SERVERS_COLUMNS: Array<{ name: string; ddl: string }> = [
+    { name: 'container_state', ddl: 'ALTER TABLE servers ADD COLUMN container_state TEXT' },
     // Base columns that shipped in the very first schema stay here for parity
     // with fresh installs — no ALTER is issued if they're already present.
     { name: 'komodo_server', ddl: 'ALTER TABLE servers ADD COLUMN komodo_server TEXT' },