EmailRepositoryImpl.syncEmails now dispatches on account type.
For JMAP accounts:
- First run: Email/query (filtered by mailbox, limit 500) + Email/get
via back-reference → upsert emails, persist state.
- Subsequent runs: Email/changes → fetch new/updated via Email/get,
delete destroyed rows, update state in sync_state.
Maps JMAP keywords ($seen, $flagged), mailboxIds, addresses, and
hasAttachment to the existing Emails table. uid stored as 0 for
JMAP emails (unused; JMAP operations go through Email/set in Step 7).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
