feat(db & e2e): Enhance DB Schemas/Controllers and Improve E2E Tests (#966)

* feat: add global teardown to remove test data and add registration/log-out to auth flow

* refactor(models/Conversation): index user field and add JSDoc to deleteConvos

* refactor: add user index to message schema and ensure user is saved to each Message

* refactor: add user to each saveMessage call

* fix: handle case where title is null in zod schema

* feat(e2e): ensure messages are deleted on cleanUp

* fix: set last convo for all endpoints on conversation update

* fix: enable registration for CI env

e2e/playwright.config.ts

@@ -6,6 +6,7 @@ dotenv.config();
 
 export default defineConfig({
   globalSetup: require.resolve('./setup/global-setup'),
+  globalTeardown: require.resolve('./setup/global-teardown'),
   testDir: 'specs/',
   outputDir: 'specs/.test-results',
   /* Run tests in files in parallel.
@@ -61,8 +62,10 @@ export default defineConfig({
     reuseExistingServer: true,
     env: {
       ...process.env,
+      SEARCH: 'false',
       NODE_ENV: 'development',
       SESSION_EXPIRY: '60000',
+      ALLOW_REGISTRATION: 'true',
       REFRESH_TOKEN_EXPIRY: '300000',
     },
   },