#emit's listeners (ACP's #handleLifetimeEvent -> #pushConfigOptionUpdate
-> #buildConfigOptions) run synchronously up to their first await, and
#buildConfigOptions is evaluated as a synchronous argument expression
before that await. Emitting model_changed immediately after
agent.setModel(previousModel) but before #models.restoreThinkingSnapshot
ran meant ACP could push a { previousModel, target-session-thinking }
config that was never an actual session state -- neither the failed
target nor the restored previous session.
Move the emit after restoreThinkingSnapshot/restoreServiceTiers so it
observes fully-restored state, same as every other rollback consumer
in this catch block already does implicitly by running after both.
Found by Codex on PR #6908 (pullrequestreview-4801303428), against
a33aa07df from this same branch.
bun test test/acp-agent.test.ts (57) + agent-session-switch-prev-context,
agent-session-model-persistence, agent-session-model-switch-auth,
agent-session-openai-completions-model-switch, nonvision-model-switch
-- 90 pass, 0 fail. Workspace typecheck clean.
(cherry picked from commit 0ac190a39a1687ebf85849dde5e1af9c2f9147fc)
