In Telegram forum-enabled groups, the General topic does not include
message_thread_id in incoming messages (it is None). This caused:
1. Messages in General losing thread context — replies went to wrong place
2. Typing indicator failing because thread_id=1 was rejected by Telegram
Fix: synthesize thread_id="1" for forum groups when message_thread_id
is None, then handle it correctly per operation:
- send: omit message_thread_id (Telegram rejects thread_id=1 for sends)
- typing: pass thread_id=1, retry without it on "thread not found"
Also centralizes thread_id extraction into _metadata_thread_id() across
all send methods (send, send_voice, send_image, send_document, send_video,
send_animation, send_photo), replacing ~10 duplicate patterns.
Salvaged from PR #7892 by @corazzione.
Closes#7877, closes#7519.
When sending multi-chunk responses, individual chunks can fail due to
transient iLink API errors. Previously a single failure would abort the
entire message. Now each chunk is retried with linear backoff before
giving up, and the same client_id is reused across retries for
server-side deduplication.
Configurable via config.yaml (platforms.weixin.extra) or env vars:
- send_chunk_delay_seconds (default 0.35s) — pacing between chunks
- send_chunk_retries (default 2) — max retry attempts per chunk
- send_chunk_retry_delay_seconds (default 1.0s) — base retry delay
Replaces the hardcoded 0.3s inter-chunk delay from #7903.
Salvaged from PR #7899 by @corazzione. Fixes#7836.
Markus Corazzione