---
model: openai/gpt-5.6-sol
service: opencode
timestamp: 2026-09-03T20:54:04Z
git_ref: aadfd1cf
diff_cmd: git diff HEAD
---

## Generated changes

> `git diff HEAD -- piker/ui/_exec.py piker/ui/_window.py`

Extracts nonblocking `start_qtractor()` from the blocking CLI adapter.
The returned `QtractorSession` exposes the production window and central
widget, the Trio token and cancellation scope, readiness and completion
Qt signals, the final `outcome.Outcome`, Qt-loop ownership, and an
idempotent structured shutdown request. Caller-owned Qt application
state and installed callbacks are restored when the guest completes.
`MainWindow.closeEvent()` retains geometry persistence but delegates
runtime teardown through the injected callback instead of sending
process-wide SIGINT.

> `git diff HEAD -- piker/ui/_app.py`

Publishes application readiness only after initial symbol loading,
order-mode startup, search registration, provider-search task startup,
input handler entry, and startup-status removal.

> `git diff HEAD -- tests/ui/test_qtractor.py`

Adds a provider-independent lifecycle regression which runs two real
Tractor root runtimes in sequence on pytest's unique registry. Real
window-close events drive structured cancellation while signal, outcome,
task-finalization, global-window, runtime, and shared-QApplication
assertions prove restartable teardown without an interlayer fake.

Human review then brought the generated Python into project style:
boolean connectives use dedicated vertical lines, opaque helper returns
and control-flow targets carry local annotations, and Qt disconnect
failures are logged instead of silently suppressed.

## Verification

- Ruff passes for all four changed Python files.
- Python static compilation and `git diff --check` pass.
- The first focused run exposed the test widget's missing production
  `on_win_resize()` contract; the narrow test widget was corrected.
- The focused lifecycle regression passes with two sequential real
  Tractor sessions.
- The combined UI harness and lifecycle run passes: 3 tests and two
  upstream Tractor `Registrar.uid` deprecation warnings.
- A post-pass attempt to disconnect a pre-existing Qt signal proxy
  segfaulted during PyQt teardown and was fully reverted; it is not part
  of this patch. The restored lifecycle regression passes again.
- All automated Qt execution used `--headless` and the offscreen
  platform.
- The approved `nix develop` shell hook unexpectedly provisioned the
  ignored worktree-local `py313/` environment; no tracked dependency or
  lock files changed.