fix(gmail): add gmail.modify scope for label and modify operations

Without gmail.modify, archive/mark and the new label CRUD + apply/remove
commands fail with "insufficient authentication scopes". Existing
profiles must be re-added (agentio gmail profile add --profile <name>)
to consent to the broader scope.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: plosson

src/auth/oauth.ts

@@ -7,6 +7,7 @@ const GMAIL_SCOPES = [
   'https://www.googleapis.com/auth/gmail.readonly',  // search & read emails
   'https://www.googleapis.com/auth/gmail.send',      // send emails
   'https://www.googleapis.com/auth/gmail.compose',   // create/update drafts
+  'https://www.googleapis.com/auth/gmail.modify',    // archive, mark read/unread, label CRUD, modify labels on messages/threads
   'https://www.googleapis.com/auth/userinfo.email',  // get email for profile naming
 ];