hermes - 💡(How to fix) Fix weixin: ret=-2 errmsg="rate limited" also indicates stale context_token (follow-up to #18100) [2 pull requests]

Problem

The Weixin adapter's _is_stale_session_ret() helper recognizes two variants of stale context_token:

1. ret=-2 errmsg="unknown error" — fixed in #17432
2. ret=-2 errmsg=None/"" — reported in #18100

We encountered a third variant that is also missed:

WARNING gateway.platforms.weixin: [Weixin] rate limited for o9cq80zX; backing off 3.0s before retry
ERROR   gateway.platforms.weixin: [Weixin] send failed to=o9cq80zX: iLink sendmessage rate limited: ret=-2 errcode=None errmsg=rate limited

This is the same stale-session signal — not a genuine rate limit. Recovery pattern is identical: after the user sends an inbound message (which refreshes context_token), subsequent sends succeed immediately.

Root Cause

_is_stale_session_ret() in gateway/platforms/weixin.py checks:

msg = (errmsg or "").strip().lower()
if not msg:
    return True
return msg == "unknown error"

When errmsg is "rate limited", it falls through to the rate-limit backoff path, burning all retries against the dead token.

Proposed Fix

Widen the check to also treat "rate limited" as a stale-session signal:

if not msg:
    return True
return msg in ("unknown error", "rate limited")

Environment

• Hermes Agent v0.13.0
• Weixin iLink adapter
• iLink endpoint: https://ilinkai.weixin.qq.com

References

• #17228 — original discovery (errmsg="unknown error")
• #18100 — empty errmsg variant
• #17432 — merged fix for variant 1