mohamed-elkholy95 7ebf611be8 fix(transcription): retry Whisper calls and guard malformed responses
A single transient failure between the agent and an OpenAI/Groq Whisper
endpoint currently vanishes as `return ""` in transcribe(). The voice
message arrives as the empty string and there is no way to tell real
silence apart from a failed upload. A malformed but successful response
body is even worse: the JSON-decode error escapes the helper unhandled.

Add a shared `_post_transcription_with_retry` used by both providers.

Retry behaviour:
  - exponential backoff 1s -> 2s -> 4s, up to 3 retries (4 attempts)
  - retryable HTTP statuses: 408, 429, 500, 502, 503, 504
  - retryable exceptions: TimeoutException, ConnectError, ReadError,
    WriteError, RemoteProtocolError

Non-transient failures short-circuit to "" on the first attempt --
retrying a misconfigured key or a broken upload only burns rate-limit
quota. Branches that short-circuit:
  - missing API key, missing audio file
  - file-read errors (PermissionError, OSError) on the audio path,
    preserving the nightly contract for direct provider callers
  - HTTP auth/4xx body issues via raise_for_status()
  - response.json() parse failures
  - non-dict JSON payloads

Sharing one helper means OpenAI and Groq cannot drift apart silently.

Thread `language` through the helper. The multipart files dict is rebuilt
inside the per-attempt loop, so when a caller sets self.language the
`language` field is sent on every attempt -- not just the first.

Tests cover:
  - every advertised retryable status and exception, parameterized
  - language present on attempts 1 and 2 of a 503->200 sequence
  - language absent when unset; present when set (both providers)
  - malformed JSON body and non-dict JSON body short-circuit to ""
  - PermissionError on file read short-circuits with no HTTP attempt
  - max-attempts give-up, exponential-backoff schedule, auth no-retry,
    missing-key / missing-file short-circuit

Test stub fix: the _StubResponse in tests/channels/test_channel_plugins.py
declared no status_code, which the new helper reads for retry classification.
Set status_code = 200 so the stub advertises the successful response that
those tests already simulate. Also moved the two transcription-provider
imports to the top of that file (previously placed mid-file) so the file
is ruff-clean (E402).
2026-05-06 15:52:25 +08:00
..
2026-05-06 00:43:00 +08:00