The reported bug (2026-09-28): every chat ran glm-5.3-flash regardless of
any pick, while composer and settings UIs agreed with each other and lied
about the run. Root cause: a fossil default-settings record (settings.json
chat section, frozen pre-slots-wave) was stamped verbatim into every new
chat at birth by the new-session flow, and resolveConversationSpec prefers
the per-chat record over the strong slot forever.
Owner redesign — models are per session, always; the strong slot is the
new-session default:
- POST /api/chats stamps the newborn verbatim from the strong slot
(model + thinking level); no client settings PUT on create anymore
- the composer control is dual-bound: in-session it reads/writes the
session's own record (GET /api/chats/:id, PUT .../settings); on the
draft surfaces it binds the strong slot (picking there = changing the
default)
- thinking levels follow the identical mechanics (confirmed by owner)
- the zombie default-settings system dies whole: useDefaultSettings,
/api/settings/defaults, src/store/default-settings.ts, the chat
section of UserSettings (sanitizer strips fossil copies), the legacy
default-settings.json fold, and DEFAULT_SETTINGS_FILE
- catalogDefaultsFor collapses to the strong slot alone
- thinking display for a legacy unstamped session resolves exactly like
the engine (session ?? strong ?? model ladder)
Tests: new chat-birth-stamp suite pins the stamp, the unconfigured boot,
the unset level, and the copy-not-live-view regression; defaults pins
rewritten strong-only; legacy-migration suite deleted.
