test(e2e): on the real WSL lane, background work never starts the stopped distro (E9 guard) (#35590)

* test(e2e): on the real WSL lane, background work never starts the stopped distro (E9 guard)

The Windows real-WSL lane opens a project inside its own imported distro, terminates that distro,
and runs a window of background work elsewhere (focus/blur/reveal, workspace switches, a linked
issue/PR card, Settings panes, Tasks, account switches). Every child the main process starts is
logged; no wsl.exe may run anything in the distro (listings are fine), and `wsl --list --running`,
watched each second, must never show it, which also catches UNC touches. Opening a terminal in the
WSL workspace then starts it. A participation check fails the lane if the guard skipped.

* test(e2e): actually render each Settings pane in the WSL lane's E9 background window

openSettingsTarget alone only set the navigation target, so no pane mounted and none of its reads
(servers, accounts, agents, integrations, CLI status, the repo pane's orca.yaml check) ran. Open
Settings, wait for each pane's section to mount, then close it.

* test(e2e): harden the WSL lane's E9 guard per review

- process-host logs every spawn to ORCA_E2E_SPAWN_LOG when set, so the guard sees worker-thread
  and inheriting-child spawns (e.g. the Codex rate-limit fetch), sync ones included.
- The spawn baseline is taken before `wsl --terminate`, and the running-list watcher starts right
  after it, so work in the stopping window counts.
- A wsl.exe launch counts as starting the distro unless it names another or only lists/terminates.
- The watcher is async with a 5 s timeout and non-overlapping ticks; a failed read is retried and
  fails the guard after three, never reads as "stopped". The recorder throws if it cannot hook,
  and the spawn log must be non-empty. The doc names the watcher as the authoritative assertion.

* test(e2e): bound the terminate grace, keep the spawn log out of shipped runs, tolerate torn lines

- The watcher forgives running reads only within 3 s of `--terminate` and before its first
  not-running read, which the rounds now await; any running read after it fails the guard.
- Main drops ORCA_E2E_SPAWN_LOG outside e2e mode (no ORCA_E2E_USER_DATA_DIR) before anything
  spawns, so no daemon, PTY or agent inherits it; the log holds full argv, tests only.
- readSpawnLog skips a line torn by a concurrent append.

* test(e2e): no blocking wsl.exe in the WSL lane's E9 guard, and a timeline for failures

The first lane run was cancelled at the 30-minute job limit while the guard step had run 25
minutes: past three 5-minute test timeouts, which only a blocked worker survives. Every wsl.exe
call (setup, terminate, cleanup) is now async with a timeout, so a hung one fails the test. The
guard logs a timestamped timeline (each running-list read, terminate, rounds) for diagnosis, and
the job limit goes to 50 minutes for the three added runs.

* test(e2e): let the setup's own WSL terminal launch settle before the terminate; 10 s grace

The lane run failed with "Ubuntu was still listed 3000 ms after --terminate" in all three runs.
The timeline showed why: focusing the WSL workspace in setup is a user act that opens a WSL
terminal, and its launch (codex trust probe, PTY, hook relay) landed about a second after the
terminate and restarted the distro. Setup now waits for that terminal's PTY and for wsl.exe
launches to go quiet for 3 s before terminating. The grace is two running-list reads (10 s).

* test(e2e): interleave wsl.exe launches into the E9 guard's timeline

The lane saw the distro boot about two seconds after the terminate with nothing naming the
launcher; each running-list tick now also prints the wsl.exe launches logged since the last one.

* test(e2e): time and stack every logged spawn and main's WSL UNC touches

The E9 guard printed spawns at its poll time, up to a second late, and with
no caller. Each record now carries when it happened and the caller's stack,
and main's fs touches of \\wsl.localhost paths are logged too, so a boot
with no wsl.exe launch before it can still be attributed.

* test(e2e): keep spawn-log stacks and main's fs hooks strictly to e2e mode

process-host now writes the spawn log, and captures caller stacks, only when
ORCA_E2E_USER_DATA_DIR is set as well, so a stray log variable in a CLI or
daemon environment does nothing. The main-process fs/spawn hook refuses to
install outside an e2e-mode app, and a source scan pins that no shipped code
imports or installs it.

* test(e2e): guard a focused WSL workspace left idle through the stop

Device runs saw a stopped distro restart with its bridge workspace focused
and nothing touched: the stop's own fallout re-ran renderer reads as user
acts. The new case keeps that workspace focused with a folder expanded in
the Explorer and Source Control shown, terminates, and idles. Shared guard
helpers move to tests/e2e/helpers/wsl-boot-guard.ts.

* test(e2e): capture caller stacks deep enough to reach the IPC handler

* test(e2e): give the focused-idle guard's timeout bump its reason

.github/workflows/windows-wsl-e2e.yml

@@ -26,7 +26,8 @@ concurrency:
 jobs:
   wsl-terminal:
     runs-on: windows-2022
-    timeout-minutes: 30
+    # The E9 guard adds three ~2-5 minute runs to the launch, paste and image checks.
+    timeout-minutes: 50
     env:
       NODE_OPTIONS: --max-old-space-size=4096
     steps:
@@ -75,6 +76,26 @@ jobs:
           --output=test-results/terminal-images
           --repeat-each=3
           --workers=1
+      - name: Guard that background work never starts the stopped WSL distro
+        env:
+          SKIP_BUILD: '1'
+          ORCA_BACKGROUND_LAUNCH: '1'
+          ORCA_E2E_FORWARD_APP_LOGS: '1'
+          # The spec terminates this distro; it is the one this job imported.
+          ORCA_E2E_WSL_TERMINATE_DISTRO: Ubuntu
+          PLAYWRIGHT_JSON_OUTPUT_FILE: test-results/wsl-no-background-boot-results.json
+        run: >-
+          pnpm exec playwright test
+          tests/e2e/wsl-bridge-no-background-boot.spec.ts
+          --config tests/playwright.config.ts
+          --project=electron-headless
+          --output=test-results/wsl-no-background-boot
+          --repeat-each=3
+          --workers=1
+          --reporter=list,json
+      - name: Require all three E9 guard executions
+        if: always()
+        run: node config/scripts/verify-wsl-no-background-boot-participation.mjs test-results/wsl-no-background-boot-results.json
       - name: Upload terminal image proof
         uses: actions/upload-artifact@v7
         if: always()