## Problem
Production logs show repeated EnableBanking 429s on the same
connections, every cron cycle:
```
[2026-05-04 18:00:55] EnableBanking API error status:429
body: [HUB046] Allowed number of accesses exceeded for consent
[2026-05-04 21:47:12] EnableBanking API error status:429
body: Daily PSU not present consultation limit has been exceeded
[2026-05-05 00:01:41] same connection, same error
[2026-05-05 06:01:41] same connection, same error
```
Root cause: `SyncBankingConnectionJob` returned early on 429s without
persisting any backoff state. The scheduler kept re-dispatching the same
connection on every run, hammering the provider and burning the daily
quota.
## Fix
Persist a per-connection backoff window so the scheduler stops
re-dispatching until the provider quota resets.
- New `rate_limited_until` column on `banking_connections`.
- On 429: derive the window from
1. `Retry-After` header if present,
2. "Daily ..." message → next UTC midnight (matches PSU daily limit
semantics),
3. default 1 hour (consent / generic).
- Job short-circuits with a `Skipped` sync log if the window is still
active.
- Successful sync clears the window.
- `SyncAllBankingConnectionsJob` + `SyncBankingConnections` command
filter out connections still inside their backoff.
## Tests
- Existing rate-limit test updated (now also asserts the backoff is
set).
- New: daily message → next UTC midnight.
- New: `Retry-After` header honoured (1800s).
- New: rate-limited connection skipped without calling provider.
- New: successful sync clears `rate_limited_until`.
- New: scheduler excludes connections whose backoff has not expired.
`php artisan test --compact
--filter="SyncBankingConnectionJobTest|SyncRetryAndLoggingTest|SyncBankingConnectionsCommandTest"`
→ 70 passed.