Wahab can now enter historical tickets that keep their true reported date:
- Add nullable tickets.reported_at (DateTime) via alembic d5e0f2a1c3b4;
backfill existing rows from created_at so nothing shows empty.
- TicketCreate.reported_at (optional) is persisted by create_ticket and
defaults to now when omitted, so existing create behavior is unchanged.
- New-issue form gains a 'Reported Date' date picker (defaults to today,
past dates allowed, future blocked) and sends reported_at in the payload.
- List and detail pages show 'Reported' next to 'Created' (date-only,
labeled) so backdated tickets are obvious; SLA deadline is unchanged and
still runs from creation time so backfilling never instantly breaches.
- Tests: backdated create persists + is exposed on list/detail; omitted
reported_at defaults to now; SLA window unchanged; full datetime round trip.
root