Fix merge conflicts and add withTransaction helper

- Add withTransaction helper that gracefully handles nested transactions
  (reuses existing transaction in tests, starts new one otherwise)
- Update auth procedures to use withTransaction instead of direct .transaction()
- Add email config to all e2e test contexts (required by merged code)
- Remove duplicate verification token code from signup procedure

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

packages/db/src/index.ts

@@ -33,6 +33,10 @@ export {
   parseToken,
   TOKEN_PREFIX,
 } from "./helpers/token.js";
+export {
+  type DbConnection,
+  withTransaction,
+} from "./helpers/with-transaction.js";
 /**
  * Export model operations
  */