* fix: detect additional context overflow error patterns to prevent leak to user
Fixes#9951
The error 'input length and max_tokens exceed context limit: 170636 +
34048 > 200000' was not caught by isContextOverflowError() and leaked
to users via formatAssistantErrorText()'s invalidRequest fallback.
Add three new patterns to isContextOverflowError():
- 'exceed context limit' (direct match)
- 'exceeds the model\'s maximum context'
- max_tokens/input length + exceed + context (compound match)
These are now rewritten to the friendly context overflow message.
* Overflow: add regression tests and changelog credits
* Update CHANGELOG.md
* Update pi-embedded-helpers.isbillingerrormessage.test.ts
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Co-authored-by: echoVic <AkiraVic@outlook.com>
Co-authored-by: Vincent Koc <vincentkoc@ieee.org>
* fix: treat HTTP 502/503/504 as failover-eligible (timeout reason)
When a model API returns 502 Bad Gateway, 503 Service Unavailable, or
504 Gateway Timeout, the error object carries the status code directly.
resolveFailoverReasonFromError() only checked 402/429/401/403/408/400,
so 5xx server errors fell through to message-based classification which
requires the status code to appear at the start of the error message.
Many API SDKs (Google, Anthropic) set err.status = 503 without prefixing
the message with '503', so the message classifier never matched and
failover never triggered — the run retried the same broken model.
Add 502/503/504 to the status-code branch, returning 'timeout' (matching
the existing behavior of isTransientHttpError in the message classifier).
Fixes#20999
* Changelog: add failover 502/503/504 note with credits
* Failover: classify HTTP 504 as transient in message parser
* Changelog: credit taw0002 and vincentkoc for failover fix
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Co-authored-by: Vincent Koc <vincentkoc@ieee.org>
