fix(test): Fix DATABASE_URL environment setup for integration tests

Fixes integration test failures caused by missing DATABASE_URL environment variable.

Changes:
- Add dotenv as dev dependency to load .env.test in vitest setup
- Add .env.test to .gitignore to prevent committing test credentials
- Create .env.test.example with warning comments for documentation
- Add conditional test skipping when DATABASE_URL is not available
- Add DATABASE_URL format validation in vitest setup
- Add error handling to test cleanup to prevent silent failures
- Remove filesystem path disclosure from error messages

The fix allows integration tests to:
- Load DATABASE_URL from .env.test locally for developers with database setup
- Skip gracefully if DATABASE_URL is not available (no database running)
- Connect to postgres service in CI where DATABASE_URL is explicitly provided

Tests affected: auth-rls.integration.spec.ts and other integration tests
requiring real database connections.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pnpm-lock.yaml

@@ -244,6 +244,9 @@ importers:
       '@vitest/coverage-v8':
         specifier: ^4.0.18
         version: 4.0.18(vitest@4.0.18(@opentelemetry/api@1.9.0)(@types/node@22.19.7)(jiti@2.6.1)(jsdom@26.1.0)(terser@5.46.0)(tsx@4.21.0)(yaml@2.8.2))
+      dotenv:
+        specifier: ^17.2.4
+        version: 17.2.4
       express:
         specifier: ^5.2.1
         version: 5.2.1
@@ -4103,8 +4106,8 @@ packages:
     resolution: {integrity: sha512-uBq4egWHTcTt33a72vpSG0z3HnPuIl6NqYcTrKEg2azoEyl2hpW0zqlxysq2pK9HlDIHyHyakeYaYnSAwd8bow==}
     engines: {node: '>=12'}
 
-  dotenv@17.2.3:
-    resolution: {integrity: sha512-JVUnt+DUIzu87TABbhPmNfVdBDt18BLOWjMUFJMSi/Qqg7NTYtabbvSNJGOJ7afbRuv9D/lngizHtP7QyLQ+9w==}
+  dotenv@17.2.4:
+    resolution: {integrity: sha512-mudtfb4zRB4bVvdj0xRo+e6duH1csJRM8IukBqfTRvHotn9+LBXB8ynAidP9zHqoRC/fsllXgk4kCKlR21fIhw==}
     engines: {node: '>=12'}
 
   drizzle-orm@0.41.0:
@@ -7040,7 +7043,7 @@ snapshots:
       c12: 3.3.3(magicast@0.3.5)
       chalk: 5.6.2
       commander: 12.1.0
-      dotenv: 17.2.3
+      dotenv: 17.2.4
       drizzle-orm: 0.41.0(@opentelemetry/api@1.9.0)(@prisma/client@6.19.2(prisma@6.19.2(magicast@0.3.5)(typescript@5.9.3))(typescript@5.9.3))(@types/pg@8.16.0)(better-sqlite3@12.6.2)(kysely@0.28.10)(pg@8.17.2)(prisma@6.19.2(magicast@0.3.5)(typescript@5.9.3))
       open: 10.2.0
       pg: 8.17.2
@@ -10150,7 +10153,7 @@ snapshots:
       chokidar: 5.0.0
       confbox: 0.2.2
       defu: 6.1.4
-      dotenv: 17.2.3
+      dotenv: 17.2.4
       exsolve: 1.0.8
       giget: 2.0.0
       jiti: 2.6.1
@@ -10748,7 +10751,7 @@ snapshots:
 
   dotenv@16.6.1: {}
 
-  dotenv@17.2.3: {}
+  dotenv@17.2.4: {}
 
   drizzle-orm@0.41.0(@opentelemetry/api@1.9.0)(@prisma/client@6.19.2(prisma@6.19.2(magicast@0.3.5)(typescript@5.9.3))(typescript@5.9.3))(@types/pg@8.16.0)(better-sqlite3@12.6.2)(kysely@0.28.10)(pg@8.17.2)(prisma@6.19.2(magicast@0.3.5)(typescript@5.9.3)):
     optionalDependencies: