PR #33344 runtime verification
main: 76b3e3390e
PR: f7f53c90cd647d565626df6108bcef7139fe86da
Linux, system Google Chrome, dependency Playwright, Pi 1.5.2

Browser flow on each revision:
- Add local folder /home/user/t3code as project.
- Select Codex gpt-6.1-sol and submit the same no-tools prompt.
  Both returned: baseline codex provider path works.
- Add real Pi provider with launch args --session-dir /dev/null/pi-pr33344.
- Create a thread, select Pi default and submit the same prompt.

Main client: Pi RPC read failed: pi process exited with code 1.
Main server: no ENOTDIR diagnostic; no Pi process closed stdout warning.

PR server, first failed session-start attempt:
[00:43:24.475] WARN (#5162): Pi process closed stdout.
  {
    detail: 'pi process exited with code 1\n' +
      "Error: ENOTDIR: not a directory, mkdir '/dev/null/pi-pr33344'\n" +
      'at mkdirSync (node:fs:1410:26)\n' +
      'at new _SessionManager ([redacted]\n' +
      'at _SessionManager.create ([redacted]'
  }

PR client: same error and three frames are visible.
The orchestration retries session start five times on both revisions.

Additional real crash using --session-dir /dev/null/token=<harmless-canary>:
PR client/server retained ENOTDIR and replaced the token remainder with [redacted].
Canary string absent from captured server log.

Healthy Pi session with a valid session directory started, but the local
proxy returned: stream error: upstream terminated with incomplete empty response (0 tokens).
No additional Pi stdout-close warning was emitted for those model API errors.
Successful Pi generation is unverified.

blacksmith-check run --id <task-worker> 'vp i && vp test run packages/provider-pi/src/server/rpc.test.ts'
Test Files 1 passed (1)
Tests 59 passed (59)