* feat: expose msg_limit ceiling via /api/session metadata, frontend reads dynamically (#6177)
Backend exposes _MAX_MSG_LIMIT as _msg_limit_max in every /api/session
response. Frontend reads it dynamically, falling back to _MSG_LIMIT_MAX
for older servers. This removes the hand-mirrored coupling between the
two layers.
Removed test_msg_limit_ceiling_drift.py since the mirror pattern that
required the drift guard is replaced by dynamic metadata.
This is the standalone metadata-decoupling piece from #6206,
without the clamp/paging that already shipped in exp-v0.52.98 via #6152/#6154.
* fix(session): declare _msgLimitMax at module scope + CHANGELOG + gate fixes (#6214 follow-up)
The submitted PR used _msgLimitMax at two read sites (boundedReloadLimit in
_ensureMessagesLoaded, useBeforePaging in _loadOlderMessages) but never declared
it and read it before assignment -> undefined on cold load -> full-transcript
fetch every load (regression) + implicit global. Declared `let _msgLimitMax =
_MSG_LIMIT_MAX;` at module scope so the reload-width paths always read a defined
value (the static fallback) until the server's _msg_limit_max lands.
Also: defined the ceiling globals in the two inline node-harness tests that copy
_ensureMessagesLoaded's body (test_cross_session_message_load_isolation,
test_session_unread_dot_on_visit), updated the source-string assertion in
test_webui_external_refresh_frontend, and added 3 decoupling tests (backend field
present, module-scope declaration + fallback, both paths read the live ceiling)
replacing the deleted drift-guard.
Gate: Codex adversarial SAFE TO SHIP (executable probes: cold-load fallback,
mixed-version omission, live update, cross-session isolation, over-ceiling bare
refresh, msg_before row preservation). Full sharded suite green.
Co-authored-by: webtecnica <webtecnica@users.noreply.github.com>
---------
Co-authored-by: webtecnica <webtecnica@users.noreply.github.com>
Co-authored-by: nesquena-hermes <agent@nesquena-hermes>
