iris bench: cancelled gestures, flinging on every axis, and rows that change height (ai-app-2 a2e5e58)

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

README.md

@@ -11,6 +11,41 @@ no enrolment and no permissions.
 
 The rest of this file is the runbook that was delivered with the APKs.
 
+**2026-09-08 (late): the four defects from your second report.**
+`iris-bench-arm64.apk` rebuilt from ai-app-2 `a2e5e58`. Everything here
+comes from the report you sent, and each one has a test that fails
+without the change -- but the phone is the only place three of them were
+ever seen, so they want checking there.
+
+- **"Leaving and reopening the app also randomly moved the vertical
+  scroll."** The system's own swipe up from the bottom edge to leave the
+  app was reaching iris as an ordinary flick *released at speed*, so the
+  transcript flung while the app was in the background and you came back
+  to a different place. A gesture the platform takes away is now a
+  cancel rather than a release: no tap, no selection, no fling derived
+  from it. What to try: scroll to somewhere you can recognise, swipe up
+  to leave, come back -- it should be where you left it.
+- **"Flinging doesn't work in horizontal scroll areas."** It does now,
+  and not as something a caller opts into: every scroll area flings, on
+  either axis, through the same code the vertical list already used --
+  the same curve and the same release thresholds Compose uses. Two
+  things came with it that a sideways fence had never needed: the
+  display's real density (a hardcoded value made a one-second coast run
+  for forty-five), and catching a coasting fence with a finger, which
+  now stops it at that sample instead of after a slop distance. What to
+  try: flick a code block sideways, and put a finger down on one while
+  it coasts.
+- **"Sometimes when I try to catch it while it's still moving it fails
+  to stop."** A row's text block drives the same gesture as the list
+  around it, and it was being told its own pan had been cancelled on the
+  frame that pan started -- so the drag ended the moment it began. A
+  widget that is itself driving the gesture now ignores that.
+- **A row that changes height no longer paints its background at the old
+  one.** On the frame a row's measurement disagrees with the box it was
+  offered, it is drawn again at its true box in the same frame rather
+  than the next one -- so expanding or collapsing a tool card should not
+  flash a background that is the wrong size for one frame.
+
 **2026-09-08 (evening): the crash on scrolling up, a devlog that can
 show a panic, and icons from a font iris ships.** `iris-bench-arm64.apk`
 rebuilt from ai-app-2 `9e301f3`.