Mac in the headset: end the Frame's viewer browser after Stop; relay fixes

- Chromium on the Frame outlived its last viewer window (verified: 11
  processes left after a run). Once nothing is shown, Stop ends it, unless
  Show was pressed again meanwhile; its profile is Frame Control's own.
- Relay --delay: if the agent side fails, close the viewer side too
  (review round 9).
- Docs: the final scroll run captured 57 fps; don't blame ScreenCaptureKit.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/mac-in-headset.md

@@ -204,7 +204,7 @@ about 5 ms to scroll compared with the baseline's way of measuring:
 | Scenario | Content | Input to drawn | fps drawn | Grades |
 |---|---|---|---|---|
 | test | 10.5 / 16.7 | 29.6 / 36.3 | 60 | all within target |
-| scroll | 19.8 / 27.4 | – | 55.9 | fps, late frames (4.8%) and worst gap (222 ms) only "acceptable": Wi-Fi stalls and ScreenCaptureKit's 46–53 fps from virtual displays |
+| scroll | 19.8 / 27.4 | – | 55.9 | fps, late frames (4.8%) and worst gap (222 ms) only "acceptable": Wi-Fi stalls (the Mac captured 57 fps in this run; earlier runs got 46–53 from virtual displays) |
 | type | 15.0 / 21.4 | 43.0 / 60.5 | – | all within target |
 
 Of the targets, click to photon is met without the Frame's compositor (the

scripts/macview-bench.py

@@ -172,11 +172,18 @@ class Relay:
                 await writer.drain()
             writer.close()
 
-        sender = asyncio.ensure_future(send())
-        while data := await reader.read(65536):
-            await queue.put((self.loop.time() + self.delay, data))
-        await queue.put((0, None))
-        await sender
+        async def pump():
+            while data := await reader.read(65536):
+                await queue.put((self.loop.time() + self.delay, data))
+            await queue.put((0, None))
+
+        sender, pumper = asyncio.ensure_future(send()), asyncio.ensure_future(pump())
+        done, _ = await asyncio.wait({sender, pumper}, return_when=asyncio.FIRST_COMPLETED)
+        if sender in done:  # the agent's side went away: stop reading, so the connection closes
+            pumper.cancel()
+            writer.close()
+            return
+        await sender  # the viewer's side ended: deliver what's queued first
 
     async def _shaped(self, reader, writer):  # agent -> Frame
         queue = asyncio.Queue()
@@ -461,7 +468,7 @@ def run_scenario(args, scenario, agent_port, token, frame_ssh):
             relay.loop.call_soon_threadsafe(relay.loop.stop)
         if chrome:
             chrome.terminate()
-        time.sleep(1.5)
+        time.sleep(3)  # Stop ends the Frame's viewer browser 2 s later
 
 
 def composited(f):

tests/test_macview.py

@@ -19,6 +19,7 @@ import sys
 import tempfile
 import time
 import unittest
+from unittest import mock
 from pathlib import Path
 
 ROOT = Path(__file__).resolve().parent.parent
@@ -82,6 +83,22 @@ class Helpers(unittest.TestCase):
             mv.show("display:1")
         self.assertIn("Screen Recording", str(cm.exception))
 
+    def test_stop_all_ends_the_viewer_browser_unless_shown_again(self):
+        calls = []
+        mv = frame_macview.MacView(["ssh"], lambda remote, **kw: calls.append(remote) or "", "frame")
+        mv.agent = mock.Mock(poll=lambda: None)
+        mv.call = lambda path, **kw: {"closed": 1}
+        mv.shown = {"window:5"}
+        with mock.patch.object(frame_macview.time, "sleep"):
+            gen = mv.shows
+            mv.shown.clear()
+            mv._end_viewer_browser(gen)
+            self.assertEqual(len(calls), 1)
+            self.assertIn("pkill -f '[f]rame-control/mac-view", calls[0])
+            mv.shows += 1  # Show pressed during the wait: leave the new viewer alone
+            mv._end_viewer_browser(gen)
+            self.assertEqual(len(calls), 1)
+
 
 class WS:
     """A minimal WebSocket client (masked frames out, plain frames in)."""

ui/frame_macview.py

@@ -128,6 +128,7 @@ class MacView:
         self.remote_port = None
         self.supervisor = None
         self.closing = False
+        self.shows = 0  # counts Show presses, so a late cleanup can't close a new viewer
         self.shown = set()  # sources with a viewer out there, connected or retrying
         self.browser_flags = list(BROWSER_FLAGS)
 
@@ -281,6 +282,7 @@ class MacView:
     def show(self, src, quality="balanced", width=None, height=None):
         if src != "test" and not src.startswith(("window:", "display:", "separate:")):
             raise MacViewError("Pick a window or display to show.")
+        self.shows += 1
         q = QUALITY.get(quality) or QUALITY["balanced"]
         state = self.call("/status")
         if src != "test" and not state.get("screen"):
@@ -325,7 +327,22 @@ class MacView:
             self.shown.clear()
         if not (self.agent and self.agent.poll() is None):
             return {"closed": 0}
-        return self.call("/close", method="POST", **({"src": src} if src else {}))
+        out = self.call("/close", method="POST", **({"src": src} if src else {}))
+        if not self.shown:
+            threading.Thread(target=self._end_viewer_browser, args=(self.shows,), daemon=True).start()
+        return out
+
+    def _end_viewer_browser(self, shows):
+        """Chromium on the Frame outlives its last viewer window (verified
+        2026-09-28), so once nothing is shown, end it. It runs with a profile
+        of its own, so nothing else is touched."""
+        time.sleep(2)  # the viewers close their windows first
+        if self.shown or self.shows != shows:
+            return
+        try:
+            self.run("pkill -f '[f]rame-control/mac-view|[d]ata/frame-mac-view' || true", timeout=10)
+        except Exception:
+            pass
 
     def state(self):
         reason = self.unavailable()