emrg: stop_all Restart Manager lock-owner kill (generic DeleteFile code 5 fix)

[argszero]

Summary

Fixes the generic Windows installer DeleteFile failed; code 5 root cause (rant 2026-08-17T17:55:42, supersedes the EMRG-cmdline-scan fallback #826).

Background

Installing v0.2.43 on Windows failed with DeleteFile failed; code 5 on install\lib\websockets\speedups.cp313-win_amd64.pyd. A find_lock_owner.ps1 (Restart Manager API) probe showed the actual lock owner was an external process — the browser-harness daemon (standalone uv CPython under AppData\Roaming\uv\tools, -m browser_harness.daemon). emrgd.pid/emrgd.port were empty and no -m emrg process existed, so the existing EMRG cmdline scan (17:03:38 / #826) could never see it. Root cause: a foreign process locking files under install\ — Restart Manager's lock-owner report is the general solution covering both EMRG and foreign owners.

Changes (emrg/_stop_all.py, pure stdlib — installer runs it standalone)

1. New stop_lock_owners() step — inserted in stop_all() after stop_bundled_git(), before verify():
   • PowerShell + Restart Manager (rstrtmgr.dll, C# wrapper ported from the verified find_lock_owner.ps1) scans $env:USERPROFILE\.emrg\install\ recursively for locked-file owners, deduped PID set.
   • Performance: batches of 500 files per RmRegisterResources in one session; RmGetList retries on ERROR_MORE_DATA (234) with a grown buffer — no per-file session (10k+ files under install).
   • Safety: excludes self + the full ancestor chain (the running install\python-dist\python.exe loads python313.dll etc. from install; ancestors include the Inno setup.exe — never killed) via Win32_Process ParentProcessId walk.
   • Remaining PIDs: Stop-Process -Force, printing PID name cmdline (truncated 150 chars) — clearly telling the user a non-EMRG process (e.g. browser-harness daemon) was stopped; emits a restart hint when browser-harness was killed.
   • RM unavailable (permissions/API failure) → silently skipped, best-effort like every other stop step.
2. _verify_windows() extension — re-runs the same Restart Manager scan; any remaining non-self/ancestor lock owner is appended as file-lock owner (pid N, name) → exit 1 (installer abort semantics R125 unchanged).
3. Template is fully static (no str.format) so the literal PowerShell/C# braces need no {{ }} escaping.

Tests

+9 (Agent.md 885→893): TestLockOwners (POSIX no-op, tab-output parsing, subprocess-failure → empty, kill-flag rendering, template key elements incl. RM API/batch/234/ancestor-exclusion/truncation/hint, no-format render safety, verify residual) + order wiring (lock owners after bundled-git before verify) + installer textual wiring pin.

Full pytest 892 passed + 1 skipped (893 collected), import + CLI green.

[argszero]

✅ LGTM — cycle 594 (1/3). Re-verified: Restart Manager lock-owner scan (rstrtmgr.dll, batched 500-file RmRegisterResources, ERROR_MORE_DATA 234 retry), self+ancestor-chain exclusion (ParentProcessId walk — protects the running install\python-dist\python.exe and Inno setup.exe), Stop-Process -Force with PID/name/cmdline(150) logging + browser-harness restart hint; verify() extension reports survivors → exit 1 (R125 intact); stop order bundled-git → lock-owners → verify. Full pytest 892+1 (893), import + CLI green; CI test + test-windows PASS (32018793024).

[argszero]

✅ LGTM — cycle 595 (2/3). Re-verified head 00a27f4 unchanged (4 files +308/−2): static PS/C# template (no str.format escaping), Restart Manager scan of $env:USERPROFILE.emrg\install with batched 500-file RmRegisterResources + ERROR_MORE_DATA(234) retry; self+ancestor-chain exclusion (ParentProcessId walk protects running python-dist python + Inno setup.exe); Stop-Process -Force with PID/name/cmdline(150) logging + browser-harness restart hint; stop order bundled-git → lock-owners → verify; _verify_windows() reports surviving file-lock owners → exit 1 (R125 intact). CI test + test-windows PASS (32018793024). Awaiting 3rd LGTM.

[argszero]

✅ LGTM — cycle 596 (3/3). Re-verified head 00a27f4 unchanged (4 files +308/−2), CI test + test-windows PASS (32018793024), MERGEABLE/CLEAN. Three consecutive LGTMs from cycles 594/595/596 with no ❌ in between — merging.