Test: wait for dock child PID before session-stop checks

mseries/OS9-HANDOFF.md

@@ -1,3 +1,13 @@
+## Dock launcher regression harness startup race — 2026-10-22
+
+PR #518's validation run [39770268132](https://github.com/techmore/ElementaryOS_MSeries/actions/runs/39770268132)
+exposed a test-only race: the SIGHUP case treated creation of the fake dock's PID file as proof that its contents had
+been written. The harness now waits for a numeric PID and stops waiting if the wrapper exits. The focused launcher suite
+passes 8/8 locally. No production launcher behavior, installed software, dock service, kernel, boot or hardware state
+changed. PR #518 remains blocked on its separate source-preparation failure and base-branch conflict; wip4 has not been
+built or staged. Next: land this harness fix after review, then refresh #518 against current `dev` and retry only when its
+pinned-source preparation is viable.
+
 ## Bounded Aurora CI dependency downloads — 2026-10-22
 
 The unified72 check spent 47m17s fetching 144 MB from the Azure Ubuntu

mseries/ROADMAP.md

@@ -115,6 +115,14 @@ suspend and controlled power remain open. Read latest handoff before proceeding.
 
 # Roadmap, features and follow-ups (MacBook Pro 14" M1 Pro, elementary OS 9 on Asahi)
 
+## Dock launcher regression harness startup race — 2026-10-22
+
+The #518 PR validation run [39770268132](https://github.com/techmore/ElementaryOS_MSeries/actions/runs/39770268132)
+found that the fake dock child PID file could exist before its contents were written. The SIGHUP test now waits for a
+numeric PID and detects an early wrapper exit; the focused suite passes 8/8. This changes test synchronization only and
+does not qualify the wip4 kernel candidate. PR #518 remains conflicted with `dev`, and its unified72 source preparation
+needs a fresh successful pinned-source fetch before kernel build or payload inspection can run.
+
 ## Factory speaker protection wired into ARM64 images — 2026-10-21
 
 Ubuntu Resolute `speakersafetyd` 1.1.2-4 now ships in the Apple Silicon overlay,

mseries/dock-tests/test-launcher.py

@@ -70,10 +70,21 @@ def cleanup():
             process.wait()
         self.addCleanup(cleanup)
         deadline = time.monotonic() + 3
-        while not self.child_pid.exists() and time.monotonic() < deadline:
+        child = None
+        while time.monotonic() < deadline:
+            if process.poll() is not None:
+                break
+            try:
+                value = self.child_pid.read_text().strip()
+            except FileNotFoundError:
+                value = ''
+            if value.isdecimal():
+                child = int(value)
+                break
             time.sleep(.01)
-        self.assertTrue(self.child_pid.exists())
-        return process, int(self.child_pid.read_text())
+        self.assertIsNotNone(child, 'dock child did not publish a PID before timeout')
+        self.assertGreater(child, 0)
+        return process, child
 
     def test_user_disabled_blocks_patched_and_stock_fallback(self):
         marker = self.home / '.config/mseries/dock/user-disabled'