When `/model X` is the FIRST message after an idle/daily/suspended auto-reset,
the slash-command path stores a session model override but leaves
`session_entry.was_auto_reset = True` (it never passes through
`_handle_message_with_agent`, which is where the flag was consumed). On the
NEXT regular message, the auto-reset cleanup block pops the freshly-stored
model/reasoning override BEFORE the flag is consumed — so the switch is
silently lost and resolution falls back to the config default, while the
session DB still shows the switched model (a two-sources-of-truth divergence).
Consume the flag at both sites:
1. gateway/run.py — capture `was_auto_reset` into a local and set the
attribute False immediately at the top of the cleanup block, so the
cleanup can't re-fire on a later message and wipe an override stored
between turns. Downstream reads use the captured local.
2. gateway/slash_commands.py — the model path consumes the flag before
storing the override, so a /model-first-after-auto-reset isn't wiped by
the next message's cleanup.
Salvaged from #48062 by x7peeps (authorship preserved).
Tests: tests/gateway/test_48031_model_switch_after_auto_reset.py — AST
invariants pinning both consume sites (load-bearing; verified they fail when
either consume is removed). Mirrors the AST-pin approach in
test_35809_auto_reset_clean_context.py. Gateway session/reset suite: 16 passed.
Fixes#48031
x7peeps