Auto-skip e2e tests when TEST_DATABASE_URL is not configured

Previously, e2e tests would fail with a confusing URL parse error when
TEST_DATABASE_URL was not set. Now SKIP_DB_TESTS automatically becomes
true when the database URL is missing, gracefully skipping these tests.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/testing/test-helpers/src/skip-db-tests.ts

@@ -2,9 +2,12 @@ import { describe } from "bun:test";
 
 /**
  * Skip flag for database-dependent tests.
- * Set SKIP_DB_TESTS=1 to skip e2e tests that require a database.
+ * Tests are skipped when:
+ * - SKIP_DB_TESTS=1 is explicitly set, OR
+ * - TEST_DATABASE_URL is not configured
  */
-export const SKIP_DB_TESTS: boolean = process.env.SKIP_DB_TESTS === "1";
+export const SKIP_DB_TESTS: boolean =
+  process.env.SKIP_DB_TESTS === "1" || !process.env.TEST_DATABASE_URL;
 
 const _describeSkipIf = describe.skipIf(SKIP_DB_TESTS);