docs: egui port decision + egtest harness + winit-android redraw bug

HANDOFF.md

@@ -797,6 +797,59 @@ jank is frames that never ran. Next phone run: `jank_capture.py capture
 ... --tag <build>`; the MISS forensics (sw/sn/eage/lastage fields)
 will classify each break.
 
+### 8.11 egui port decision + egtest harness (2026-10-31)
+
+**Verdict on Slint:** stock crates.io build janky (user), vendored build
+same/worse (user), minimal sltest (300 rows, no textures) janky (user),
+adb-measured drops (0.05-0.83%) are a FLOOR — the user's finger says
+"much more than 1 hitch per 8 s". **The base Slint-on-Mali render path is
+the problem. User decision: port to egui** (different toolkit AND a
+different renderer family: glow/OpenGL-ES3 vs Skia-on-wgpu).
+
+**egtest** (`/tmp/egtest`, standalone, same discipline as sltest) — the
+CONTROL experiment: the exact sltest scene (8,580 rows × 150 px, 148 px
+color band + 2 px white separator) in egui 0.31.
+- egui_glow/egui-winit 0.31.1, glow 0.16, winit 0.30, android-activity
+  0.6, `egl` 0.2.7 safe wrapper. APK 1.98 MB. `wow.gmp.egtest`.
+- Virtualized list: only visible rows ± 4 painted per frame via the
+  painter (immediate mode = free virtualization). Momentum fling
+  (0.94 decay, 8 px/frame min, seed = last drag delta × 1.5).
+- FR log (sltest pattern, non-blocking logger, per-line flush):
+  `/sdcard/Android/data/wow.gmp.egtest/files/fr.log`.
+- Build: `cd /tmp/egtest && ADB_SERIAL=... ./scripts/build.sh [aarch64|x86_64] [install|no-install]`.
+- Crates.io naming gotcha: `egui_glow` (underscore) vs `egui-winit`
+  (dash) — the index is inconsistent; winit's android feature is
+  `android-native-activity`; cargo-apk2 needs the activity section in
+  Cargo.toml (NativeActivity + lib_name) and `config_changes` as a
+  pipe string of aapt2 flag NAMES (no `keyboardNavigation` — it's
+  `navigation`; hex/decimal bitmasks rejected).
+
+**Two real phone bugs found + fixed (they will bite the final port too):**
+1. **winit 0.30 android: `RedrawRequested` is never dispatched on the
+   phone.** `MainEvent::Resume` never arrives → `EventLoopInner.running`
+   stays false → the RedrawRequested dispatch (inside `if self.running`)
+   is suppressed; `about_to_wait` is not. Emulator delivers Resume
+   fine — phone (pre-rotated display) does not. **Fix: drive frames from
+   `about_to_wait`** — render there + `ControlFlow::WaitUntil(now+8333µs)`
+   (app-owned pacing, same architecture as the Slint frame driver).
+   Phone result: ~698 frames / 10 s (≈100 Hz) rendering the scene on
+   Mali+ES3 with 1-2 ms render cost.
+2. `Window::request_redraw()` via ALooper_wake was unreliable here too —
+   the WaitUntil pacing removes the dependency entirely.
+
+**Current state (handoff):** egtest is INSTALLED on the phone but the
+phone's WM is in a degraded state (NotificationShade stuck in focus,
+`dumpsys window` broken — "Broken pipe", load avg ~6 from the user's
+apps). The app was last seen rendering into a GONE window (WM never
+granted visibility — plausibly a cascade of the stuck-shade state, not
+an app bug). **NEEDS THE USER**: glance at the phone (close the shade /
+check for a stuck system UI), then launch **Egtest** from the launcher
+and scroll it hard. Question to answer: *is egtest smooth where sltest
+(janky) rendered the identical scene?* FR log is live for drop analysis
+afterwards (`grep FR fr.log`). If smooth → port the gallery app layer
+(db/scan/turbojpeg/LRU/GPU-upload, all renderer-agnostic) to an egui
+grid + the about_to_wait frame driver + EGL setup from egtest.
+
 ### 8.8 Jank-hunt round 2 + the keep-alive incident (2026-10-28)
 
 Follow-up on "still seeing jank" (post-GPU-texture). Instrumentation: