Add cancellation and cleanup for native server creation

src/lib/server/backends/schema.ts

@@ -16,5 +16,9 @@ export function migrateNativeInstances(handle: Database.Database): void {
             stage_operation_id TEXT, operation_id TEXT, files_json TEXT,
             applied_at TEXT, verified_at TEXT
         );
+        CREATE TABLE IF NOT EXISTS native_creation_cancellations (
+            creation_id TEXT PRIMARY KEY REFERENCES server_deployments(id),
+            cleanup_id TEXT NOT NULL UNIQUE REFERENCES server_deployments(id)
+        );
     `);
 }