iris: rebuild with composing-text sync, tap-vs-swipe focus, composer rebuild

Composed text now syncs back to Gboard via updateSelection, a swipe over
the composer no longer opens the keyboard, and text survives leaving and
returning to the app. Composed text still not visible on screen -- a
separate, unfixed bug; see ai-app-2 docs/RUST.md's P0 box.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

README.md

@@ -11,6 +11,24 @@ no enrolment and no permissions.
 
 The rest of this file is the runbook that was delivered with the APKs.
 
+**2026-09-06: composing text + caret, composer layout, text survives app
+switch.** `iris-bench-arm64.apk` rebuilt on top of the fling/stream/type/
+keyboard bench v2 above (same commit range, merged). Fixes from Iris's
+phone report on the previous build: Gboard's composing keystrokes now sync
+back to the app (`InputMethodManager.updateSelection`, previously never
+called, which is why typing looked stuck until a space); swiping over the
+composer bar no longer opens the keyboard (only a completed tap does,
+confirmed on the emulator); and text no longer disappears after leaving
+and returning to the app (a genuinely new renderer now clears the CPU-side
+glyph cache instead of leaving it pointed at a destroyed GPU device). The
+composer itself was also rebuilt as one widget with a height cap and
+insets-aware bottom padding. **Not fixed**: composed/typed text still does
+not become visible on screen at all, a separate, deeper bug found while
+verifying the above -- ruled out as a widget-layout bug (a new unit test
+proves the region math is correct), still open. See ai-app-2's
+`docs/RUST.md`, P0 box, for the full account, what was verified on the
+emulator, and what still needs a real device or Vulkan to isolate.
+
 **2026-09-06: bench v2 (fling/stream/type/keyboard).** `compose-bench-arm64.apk`
 rebuilt with the four-phase benchmark Iris asked for after using v1 on her
 phone -- a real fling (12,000px/s through the list's own `FlingBehavior`,