_set_session_context() called set_session_vars() without session_id, so the
HERMES_SESSION_ID contextvar was set to "" (explicitly empty) on every
prompt.submit / session bind. The subprocess-env bridge
(_inject_session_context_env) treats an explicit "" as authoritative and does
NOT fall back to os.environ, so terminal/execute_code commands in a
dashboard/TUI/web session saw an empty $HERMES_SESSION_ID — even though
agent_init had populated it via set_current_session_id().
Every other set_session_vars() call site (gateway/run.py, cron, api_server)
passes session_id; tui_gateway was the only one that dropped it, affecting all
three of its frontends (Ink TUI, desktop, web).
Fix: derive the live id in the existing _sessions lookup loop
(agent.session_id, falling back to session_key — same derivation used at
session finalize) and pass it through to set_session_vars.
Adds tests/tui_gateway/test_session_id_injection.py covering agent id,
session_key fallback, and unknown/ephemeral key.
bo.fu
3e340d93f4