fix: lowercase OAuth handle to prevent duplicate connected accounts (#21120)

Google and Microsoft connect flows stored the provider-returned email
verbatim, so a re-auth with different casing (Sam@ vs sam@) missed the
existing-account lookup and created a duplicate. Normalize the handle to
lowercase at extraction, matching the SSO controller.

Note: not doing backfill for now

packages/twenty-server/src/engine/core-modules/auth/controllers/google-apis-auth.controller.ts

@@ -96,7 +96,7 @@ export class GoogleAPIsAuthController {
         id: workspaceId,
       });
 
-      const handle = emails[0].value;
+      const handle = emails[0].value.toLowerCase();
 
       const connectedAccountId =
         await this.googleAPIsService.refreshGoogleRefreshToken({

packages/twenty-server/src/engine/core-modules/auth/controllers/microsoft-apis-auth.controller.ts

@@ -103,7 +103,7 @@ export class MicrosoftAPIsAuthController {
         );
       }
 
-      const handle = emails[0].value;
+      const handle = emails[0].value.toLowerCase();
 
       const connectedAccountId =
         await this.microsoftAPIsService.refreshMicrosoftRefreshToken({