docs: record the phone-report fixes, follow-ups and the bundled-font API

RUST.md's P0 box gets Iris's first real-phone report (no crash) and the
four defects it found (glyph-wipe-on-first-touch, missing bold glyphs,
text far too small, status-bar inset not applied), what was fixed and
how it was verified on the emulator, and what's still open (item 1's
root cause, and the top-row height anomaly noted in the last commit).

IRIS_TODO.md gets a new "From the phone, 2026-09-06" section for the two
items explicitly deferred to a follow-up agent: no scroll momentum/fling,
and occasional jitter scrolling down.

IRIS.md gets the public-API entry for TextData's bundled fonts/
font_diagnostics, UiRenderNode::new/resize's new window_size parameter,
AndroidUiState::content_scale, AndroidAppState::on_insets_changed, and
iris_core::WgpuErrorLog.

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

docs/RUST.md

@@ -4315,6 +4315,129 @@ device.
       confirming the phase marks partition the whole run rather than
       overlapping or dropping frames between them.
 
+      **Iris's first real phone report, 2026-09-06** (the redelivered,
+      no-`force-gles` APK above): no crash. Two screenshots, before any
+      touch: headings/links/code/table all render correctly. Four defects
+      found and worked this pass:
+
+      1. **Every glyph disappears on the first tap or scroll; rectangles
+         stay drawn** (the keyboard case is the same thing -- a tap on the
+         composer). **Not root-caused this pass.** Audited `GpuTextures`'
+         atlas-grow/patch path, `ArrBuf`'s resize-on-length-change
+         contract, and the masks/move_offsets/rsc bind-group rebuild logic
+         in `core/src/render/mod.rs` against wgpu's queue-ordering
+         contract -- everything read as spec-correct (a `queue.write_texture`/
+         `write_buffer` issued before a later `queue.submit` is guaranteed
+         visible to it on the same queue, and a dropped `Buffer`/`Texture`/
+         `BindGroup` still in flight is kept alive by wgpu's own tracker).
+         No violation found by static reading; reproducing needs either
+         the phone or a Mali driver trace, neither available this pass.
+         Instrumented for the next report instead: `Device::
+         on_uncaptured_error` is now installed on the Android device
+         (`WgpuErrorLog`, `android::render::AndroidRenderer`), and
+         `IrisViewPeer::render` logs masks/moves-resized, atlas
+         pages-grown and image bind-group creates for the first 10 frames
+         after every `surface_changed` -- exactly the window this bug
+         lands in. The bench screen's new "Diagnostics" button (below)
+         surfaces the error log and adapter identity on demand.
+      2. **Bold words render as blank gaps of the correct advance width**
+         (regular, links, inline code render fine). Fixed by bundling Noto
+         Sans/Noto Sans Mono (regular/bold/italic/bold-italic, static
+         cuts, OFL) into `iris-core` and registering them ahead of the
+         platform's own fonts -- `core/src/primitive/text.rs`'s
+         `TextData::register_bundled_fonts`. Named hypothesis, not
+         confirmed on the phone: the system "Roboto" on a modern Android
+         device is the variable "Roboto Flex," and this crate's glyph
+         path (`TextData::place`) does not apply `Synthesis`/variable-axis
+         correction at all -- a bundled *static* per-style face sidesteps
+         the question rather than answering it. `TextData::font_diagnostics`
+         reports what got resolved; logged once at startup and shown on
+         the Diagnostics page.
+      3. **Text far too small** -- iris had no device-pixel-ratio handling
+         on *either* platform before this pass (grepped for `scale_factor`
+         across the whole crate: zero hits). `DisplayMetrics.density`
+         (Android) / `Window::scale_factor()` (desktop) now divides every
+         physical-pixel number (window size, touch coordinates, the
+         shader's window uniform) down to logical units before it reaches
+         layout, so a `font_size: 16.0` is 16 dp rather than 16 raw device
+         pixels on a ~3x-density phone. Cost a second, real bug found only
+         by measuring on this checkout's emulator after the first fix
+         landed: `android::view::IrisViewPeer::surface_changed`'s call
+         into `UiRenderState::resize` (the layout engine's own notion of
+         the canvas, which every widget's absolute `PixelRegion` is
+         computed against) was still being handed raw physical
+         `width`/`height`, while `AndroidRenderer`'s side of the same
+         resize had already switched to logical -- splitting layout and
+         the shader into two different units. A fixed-size widget (the
+         bench screen's `.height(56)` button row) exposed it at ~40
+         physical px against the ~147px `56 * content_scale` predicts;
+         a proportional (`rest(n)`) size hid it by adapting to whichever
+         total it was given. Both are logical now. **Not fully verified**:
+         a fresh-install emulator screenshot after both fixes shows
+         visibly larger, readable text (`docs/bench/` has neither
+         screenshot committed -- see AGENTS.md on transcripts/screenshots
+         not going in this repo -- but the before/after is described in
+         the commit), and the button row's own height still isn't
+         obviously matching `56 * content_scale` on this run -- worth a
+         second look with `ui-trace show --field box` once there's time,
+         but not a blocker for the magnitude of the original bug (3x too
+         small).
+      4. **Status-bar inset not applied** -- confirmed nothing in this
+         app ever read `insets().top` at all (`android/insets.rs` has
+         carried `Insets.top` since it was written; nothing consumed it).
+         Fixed with a new, generic hook: `AndroidAppState::
+         on_insets_changed(rsc, LogicalInsets)`, called from `render()`
+         exactly when `AndroidUiState::insets()` changes, in logical units
+         matching everything else `content_scale` now divides.
+         `BenchClient::on_insets_changed` rebuilds the root tree with
+         `Padding::top(insets.top)` on the button row -- rebuilding the
+         whole tree rather than one `WidgetPtr` slot's content, because
+         the first attempt (a `Pad` dropped into an unrelated `WidgetPtr`
+         slot with no height override of its own) did not propagate the
+         wrapped span's fixed height correctly, which is what surfaced
+         finding 3's `UiRenderState::resize` bug in the first place.
+         Verified via `ui-trace show --field box`: the button row's top
+         (150 physical px) sits 8px below `statusBarBackground`'s bottom
+         edge (142px) on this checkout's emulator.
+
+      **A named `Diagnostics` control now exists** (RUST.md's own earlier
+      ask): a third button on the bench screen's top row, filling the
+      existing benchmark-report `TextEdit` with adapter identity/backend/
+      driver, font resolution, the atlas's live view count, every
+      uncaptured wgpu error since surface creation, and the frame report
+      -- `android::render::AndroidRenderer::diagnostics_report`. Uses the
+      existing "Copy report" button/clipboard path rather than a second
+      one.
+
+      **Verified this pass, this checkout's emulator** (`EMU_GPU` default,
+      `--features force-gles` -- this cold `emu up` again enumerated zero
+      Vulkan adapters, the same pre-existing flakiness earlier boxes
+      documented, not something this pass's diff caused): `cargo fmt --all
+      -- --check`, `cargo clippy --workspace --all-targets` (zero warnings
+      beyond the pre-existing wgpu future-incompat notice), `cargo test
+      --workspace` (all passing, unchanged pure-logic counts), `cargo ndk
+      -t x86_64 -P 26 check` clean, `./run-bench.sh` end to end
+      (`frames=691`, 24/24 swipes, 400/400 streamed events, no crash),
+      fresh-install screenshots and `ui-trace` box readouts for the four
+      items above. **Not verified this pass**: the actual phone (no
+      access), and item 1's root cause (needs either the phone's next
+      Diagnostics-page report or a Mali trace).
+
+      **Recorded but not fixed this pass** (a follow-up agent takes these,
+      to avoid colliding with this pass's `bench_client.rs`/`view.rs`
+      changes) -- see `IRIS_TODO.md`'s "From the phone, 2026-09-06":
+      swiping has no momentum (stops exactly where the finger releases,
+      unlike Compose's fling), and scrolling down sometimes jitters the
+      text.
+
+      **Redelivered, 2026-09-06, later the same day.** New arm64 APK
+      (Vulkan, no `force-gles`, bundled fonts, content-scale fix,
+      Diagnostics control), same `dev.iris.android.demo.bench` id, same
+      `CN=ai-app` signing cert, copied to `~/host/bench/
+      iris-bench-arm64.apk` and `~/repos/ai-app-bench/iris/build/outputs/
+      apk/release/iris-bench-arm64.apk`; that repo's own README gained a
+      dated entry. Still not confirmed on Iris's actual phone.
+
 - [ ] **P1 — session screen parity.** History paging backward (with the
       page-boundary healing `client-core` does not have yet, below),
       `TranscriptSource`-backed cache/server stitching, jump-to-latest,