Greptile flagged that _compute_user_message_count_lazy silently returns 0
when the SQLite query fails (DB locked, missing file, schema drift).
The pre-patch compact() walked self.messages in Python and returned the
correct count without ever touching the DB, so the silent zero
fallback is a regression that breaks _looks_like_stale_zero_message_row
under contention.
Fix: helper now takes an optional messages argument. On SQLite failure
it falls back to the same in-memory walk the original code used, so
callers see the same number they'd have seen before for any session
where Session.load() populated self.messages.
Also drop the dead ('GET', '/api/session') allowlist entry flagged by
Greptile — the /api/session handler already does its own per-stage
logging via the _t0.._t6 block (with auto-log on slow requests), and
adding RequestDiagnostics on top would just duplicate the slow-request
journal entries without adding information.
The slow-request journal showed /api/profiles, /api/models, and /api/session
fire on every session click but had no per-stage timing. Add:
- RequestDiagnostics coverage for GET /api/profiles, /api/models, /api/session
- Stage markers inside /api/profiles (list / active lookup / isolated check)
- Stage markers inside /api/models (freshness routing, serialize)
- Per-stage stage-log inside get_available_models_for_session_visit that
emits a [SLOW] line when total wall time crosses HERMES_DEBUG_SLOW ms
(default 500ms) so we can pinpoint which sub-step is blocking
No behavior change. Existing _t0.._t6 timing on /api/session and the
2.5s/10s TTL on /api/sessions are unchanged. Reversible: revert commit.
A threading.Timer per RequestDiagnostics spawns one OS thread per request, held
alive until finish() cancels it. Under sustained /api/sessions poll load this
exhausts the per-process thread cap (RuntimeError: can't start new thread) and
the server stops accepting connections. Replace with a single lazy-init
watchdog daemon thread that scans pending diags every ~1s; public API
unchanged. Caps timeout-tracking at 1 thread/process regardless of request rate.
Konstantin M