PR 28988 runtime verification
main: a036489016
PR head: be7a3922bc3ceec82b84798433c356983249387a
Linux, Google Chrome, repo Playwright 1.60.0, Pi 1.5.0, local CLIProxyAPI
Real project /home/user/verification-repo added through UI on each revision.
All messages and models selected through web UI. No mocks, fixtures, or demo data.
Pi RPC audit passes bytes unchanged to the installed CLI. HTTP relay forwards bytes unchanged to real proxy; logs only model and reasoning fields.

MAIN model switch: original bug NOT reproduced
READY-1: gpt-6.1-sol, upstream reasoning.effort=xhigh
READY-2: gpt-6-luna, upstream reasoning.effort=medium
READY-3: gpt-6.1-sol, upstream reasoning.effort=xhigh
All three provider responses completed.

PR same model switch plus neighboring behavior
READY-1: gpt-6.1-sol, upstream reasoning.effort=xhigh
READY-2: gpt-6-luna, upstream reasoning.effort=medium
READY-3: gpt-6.1-sol, upstream reasoning.effort=xhigh
LOW-OK: gpt-6.1-sol, upstream reasoning.effort=low
HIGH-OK: gpt-6.1-sol, upstream reasoning.effort=high
DEFAULT-OK: gpt-6.1-sol, upstream reasoning.effort=high
All six Pi responses completed. Pi default inherited current native Sol/high state.
Codex gpt-6.1-sol (Low): CODEX-SOL-OK completed after Pi -> Codex handoff in same thread.

Interpretation
ProviderSessionManager.providerThreadLoadKey includes full model selection. Changes cause resumeThread -> Pi registerThread -> switch_session, clearing appliedThinking. Ordinary UI model switches therefore resend thinking on main too. These real-app results establish the PR path works, but do not prove the reported pre-fix bug or exercise the changed stale-cache branch in production.

Checks
blacksmith-check: vp test run packages/provider-pi/src/server/adapter.test.ts
96 passed, including all three PR thinking reapplication cases.
CI observed: 29 successful, 0 failing, 0 pending at head.
No source changes or pushes.

Not verified
Original bug on main; stale-cache branch through a reachable production path; Pi 0.73.1; native desktop/mobile; non-Linux; other providers or external services.