A session_reset (/new, /cc) that bumps the run generation while an agent
turn is in flight left the dead agent in the _running_agents slot: the
in-flight run's own release is generation-guarded and correctly returns
False, and the outer finally's sentinel-only check also missed the
leftover real agent. The session then silently dropped every subsequent
message as 'agent busy' until a full gateway restart. (#28686)
- _process_message_or_command outer finally now calls the unconditional,
idempotent _release_running_agent_state(key) on all exit paths instead
of the sentinel-vs-else branch that could strand a dead agent.
- _handle_reset_command evicts the slot right after bumping the
generation, so the zombie is cleared at reset time regardless of how
the in-flight run unwinds.
Co-authored-by: CryptoByz <cryptobyz.airdrop@gmail.com>