chengyongru 2e56fb95b6 fix(weixin): treat ret=-2 as rate limit with 60s backoff
Reference wxclawbot-cli docs: ret=-2 is a rate limit (~7 msgs / 5 min
per bot), NOT a stale session signal.  Empty/missing errmsg is the
normal rate-limit response; only 'unknown error' correlates with stale
session per hermes-agent.

Changes:
- _is_stale_session_ret: only match 'unknown error', not empty errmsg
- _send_text/_send_media_file: on ret=-2 wait 60s then retry once
  instead of retrying without context_token
- Remove stale-session retry for empty errmsg (was burning quota)
- Update tests to cover rate-limit backoff path
2026-05-08 10:09:12 +08:00
..
2026-05-06 00:43:00 +08:00