When context compaction rotates agent.session_id, it updates the gateway/tools
session context (set_current_session_id -> HERMES_SESSION_ID env + ContextVar)
but never updates the separate logging session context. The [session_id] tag on
log lines comes from hermes_logging._session_context (set once per turn in
conversation_loop.py), so post-compaction log lines in the same turn carry the
STALE old id while the message/DB/gateway state carry the new one — breaking log
correlation exactly at the compaction boundary.
Call hermes_logging.set_session_context(agent.session_id) alongside the existing
set_current_session_id, guarded so a logging failure can't regress the routing
update. Logs-only; no runtime or caching impact.
Refs #34089
