Usage/quota queries frequently showed spurious "query failed" states that
manual refresh could not clear (#3820). Root cause: all transport-level
failures were folded into Ok(success:false), so react-query's retry never
fired and the failure body poisoned the cache as regular data.
Backend:
- balance/coding_plan/subscription services now return Err for send
failures and body-read failures (read body via bytes() before
serde_json::from_slice; reqwest's json() wraps read errors as Decode,
making error-kind checks on it dead code). Auth/4xx/parse errors stay
Ok(success:false) and surface immediately.
- Script path maps transient AppError keys (request_failed /
read_response_failed) to Err; Volcengine adds a Transient call variant.
- Command layer skips snapshot persistence, usage-cache-updated emit and
tray refresh on Err so the cache bridge cannot overwrite retained data.
- Expired-credential retry propagates transient errors instead of
rewriting them as "OAuth token has expired".
Frontend:
- resolveDisplayUsage generalized to subscription quotas; 5th param is now
an options object with a `rejected` flag: stale success data retained by
react-query across rejections is re-anchored to dataUpdatedAt and expires
through the same 10-minute keep-last-good window instead of being shown
indefinitely (a total outage used to mask longer than a single 5xx).
- useSubscriptionQuota / useCodexOauthQuota gain keep-last-good with
per-scope snapshot reset; rejected queries with no displayable value
synthesize a failure placeholder carrying the real error message so
footers keep rendering a retry entry point.
- HTTP 429 is classified transient (retry-later) alongside 5xx.
- UsageScriptModal surfaces string rejections via extractErrorMessage.
Tests: 6 backend behavior tests drive real HTTP against a local listener
to pin the Err/Ok channel semantics; frontend suite extends
keepLastGoodUsage coverage (405 passing).
- useUsageQuery: retry once + keep-last-good — show the last successful
result for up to 10min when a query fails transiently (network/timeout/
HTTP 5xx), so a single blip no longer flips the card to red. Deterministic
failures (auth, empty key, unknown provider, 4xx) surface immediately and
clear the snapshot so a stale quota can't resurface after credentials change.
- bump native balance/coding-plan/subscription request timeouts 10s -> 15s
for slow cross-border endpoints.
- coding_plan: return explicit errors ("API key is empty" / "Unknown coding
plan provider") instead of a blank failure, mirroring balance.
- add unit tests for keep-last-good and transient/deterministic classification.
Polish the provider-level User-Agent override UI on the Claude and Codex forms.
- Add a shared CustomUserAgentField (label + input + preset dropdown + live
validation) so both forms stay in sync.
- Provide curated UA presets (Claude Code / Kilo Code families that pass
coding-plan UA whitelists per #3671); the first is Claude Code's real
`claude-cli/x (external, cli)` format. Whitelists gate on the name prefix,
not the version, so static values stay valid across upgrades.
- Expose presets via a dropdown to the right of the input (z-[200] so it
renders above the dialog layers) instead of inline chips.
- Move the field into the existing advanced/reasoning collapsibles.
- userAgent.ts mirrors the backend byte rule (reject only control chars;
non-ASCII is allowed) for a non-blocking inline hint.
- i18n for all four locales (zh/en/ja/zh-TW).
Jason