fix(openai): harden reset-credit refresh and account recovery

Review follow-ups on the reset-credit caching flow:

- Recover account state BEFORE (and independently of) the reset-credit
  display cache. A failed cache refresh could previously abort the run and
  leave the account rate-limited — the very reason the credit was spent
  (#3672 / #3740). The recovered account row is now returned even when the
  cache refresh fails.
- Run the post-reset bookkeeping on a detached, time-boxed context and give
  the panel reset call a larger timeout. A client abort no longer strands a
  consumed (non-refundable) credit with an unrecovered account, and the
  chained upstream calls can no longer exceed the client timeout and invite a
  retry that spends a second credit.
- Persist the reset-credit snapshot through POST /accounts/:id/quota/refresh
  instead of a side-effecting GET flag, so the write is covered by the audit
  middleware. A rejected snapshot write now degrades to cache_persisted=false
  instead of turning a successful upstream read into a 502 that left the card
  without a credit count and the reset button permanently disabled.
- Reject snapshots whose positive count carries no expiration entries, and
  drop expired credits (clamping the count) when rehydrating, so a stale
  cache can no longer light up the reset button.
- Keep nil quota / rate-limit services nil in the handler's interface fields;
  storing a nil *Service made the "not enabled" guards non-nil.
- Time-box the usage-refresh suppression and reuse handleAccountUpdated so the
  patched row also enters the auto-refresh silent window.

frontend/src/views/admin/AccountsView.vue

@@ -318,7 +318,7 @@
               :today-stats="todayStatsByAccountId[String(row.id)] ?? null"
               :today-stats-loading="todayStatsLoading"
               :manual-refresh-token="usageManualRefreshToken"
-              @account-updated="patchAccountInList"
+              @account-updated="handleAccountUpdated"
             />
           </template>
           <template #cell-proxy="{ row }">