## Why
Production log dashboards were flooded with paired `Banking sync failed`
+ `EnableBanking API error` warnings for a handful of users, recurring
on every 6-hour `banking:sync` cycle for days. Investigation (prod
`BankingSyncLog` + connection state) showed the affected connections are
**healthy and syncing daily** (`last_synced_at` = today,
`consecutive_sync_failures = 0`): the first attempt hits a transient
`ASPSP_ERROR` / `429`, and the job's retry recovers it.
So the warnings are **noise, not breakage** — but
`SyncBankingConnectionJob` logged `Banking sync failed` inside the catch
block on *every* attempt, including non-final ones that later succeed.
That's one warning per cycle for connections that sync fine, which reads
as a failure and causes alert fatigue.
## What
Gate the `Log::log(...)` call so it only fires when the connection
actually gives up:
- the **final attempt** (`attempts() >= tries`), or
- a **permanent auth error** (`isAuthError`).
Transient errors recovered by the retry are no longer logged.
Per-attempt traceability is unchanged: `BankingSyncLog` still records
every attempt (Success / Failed) in the database.
## Tests
`tests/Feature/OpenBanking/SyncRetryAndLoggingTest.php`:
- non-final attempt → `Log::log` is **not** called
- final attempt → `Log::log('error', 'Banking sync failed', ...)` **is**
called once
Full file: 24/24 passing.
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