iris is the framework alone; the app is one crate in app-rust/

Iris: "the organization of the rust rewrite is a mess right now... there
shouldn't be anything related to the app inside of iris. Iris is supposed
to be the UI framework alone." And, on the crate count: "I'm confused why
the app only code needs more than one crate though."

Nine cargo workspaces become three, and the port's project code -- which
sat in five places, four of them inside the framework -- becomes one crate,
`ai-app`, in `app-rust/`:

  client-core                -> app-rust/src/client
  iris/transcript-ui         -> app-rust/src/ui
  iris/transcript-fixture    -> app-rust/src/ui/fixture.rs + tests/ + touch/
  iris/desktop-app           -> app-rust/src/desktop + src/bin_desktop.rs
  iris/android-app           -> app-rust/src/android + android-project/
  android-shell              -> app-rust/src/shell

iris/ keeps core, macro, the iris crate, tabs-ui and rig-input, and now
mentions no session, transcript, setup or server anywhere.

Only two of the old splits had a reason that survived reading. event-model
stays a crate at the repo root because server/ depends on it too, so a
crate is what makes the backend and the app agree by construction. The two
Android .so names looked like a hard constraint -- a package produces one
library artifact -- until P2 turned out to already plan merging those two
Android apps into one; both faces now come out of libai_app.so, picked
apart by features so `--no-default-features --features shell` keeps wgpu,
parley and iris out of the Compose app's APK. docs/RUST.md's "One app
crate" has the rest, including what each remaining feature is for.

DECISIONS.md and SUBAGENTS.md move into docs/ with everything else.

Verified: ./run-tests.sh and `cd iris && cargo test` green, clippy and fmt
clean in all five workspaces, `cargo ndk -t x86_64` links libai_app.so,
build-apk.sh produces an APK that installs and launches on this checkout's
emulator (Gl ... virgl, as expected), and the phone-sized headless
screenshot renders the transcript unchanged.

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

src/default/attr.rs

@@ -1,78 +1,28 @@
 use crate::prelude::*;
-use std::time::{Duration, Instant};
-use winit::dpi::{LogicalPosition, LogicalSize};
+use winit::dpi::{PhysicalPosition, PhysicalSize};
 
-pub struct Selector;
-
-impl<Rsc: HasEvents, W: Widget + 'static> WidgetAttr<Rsc, W> for Selector
-where
-    Rsc::State: HasDefaultUiState,
-{
-    type Input = WeakWidget<TextEdit>;
-
-    fn run(rsc: &mut Rsc, container: WeakWidget<W>, id: Self::Input) {
-        rsc.register_event(container, CursorSense::click_or_drag(), move |ctx, rsc| {
-            let region = ctx.data.render.window_region(&id).unwrap();
-            let id_pos = region.top_left;
-            let container_pos = ctx.data.render.window_region(&container).unwrap().top_left;
-            let pos = ctx.data.pos + container_pos - id_pos;
-            let size = region.size();
-            select(
-                rsc,
-                ctx.data.render,
-                ctx.state,
-                id,
-                pos,
-                size,
-                ctx.data.sense.is_dragging(),
-            );
-        });
+impl<T: HasDefaultUiState> FocusHost for T {
+    fn recent_click(&mut self) -> bool {
+        crate::attr::recent_click(&mut self.default_state_mut().last_click)
     }
-}
 
-pub struct Selectable;
-
-impl<Rsc: HasEvents> WidgetAttr<Rsc, TextEdit> for Selectable
-where
-    Rsc::State: HasDefaultUiState,
-{
-    type Input = ();
-
-    fn run(rsc: &mut Rsc, id: WeakWidget<TextEdit>, _: Self::Input) {
-        rsc.register_event(id, CursorSense::click_or_drag(), move |ctx, rsc| {
-            select(
-                rsc,
-                ctx.data.render,
-                ctx.state,
-                id,
-                ctx.data.pos,
-                ctx.data.size,
-                ctx.data.sense.is_dragging(),
-            );
-        });
+    fn set_focus(&mut self, id: Option<WeakWidget<TextEdit>>) {
+        self.default_state_mut().focus = id;
     }
-}
 
-fn select(
-    rsc: &mut impl UiRsc,
-    render: &UiRenderState,
-    state: &mut impl HasDefaultUiState,
-    id: WeakWidget<TextEdit>,
-    pos: Vec2,
-    size: Vec2,
-    dragging: bool,
-) {
-    let state = state.default_state_mut();
-    let now = Instant::now();
-    let recent = (now - state.last_click) < Duration::from_millis(300);
-    state.last_click = now;
-    id.edit(rsc).select(pos, size, dragging, recent);
-    if let Some(region) = render.window_region(&id) {
+    fn is_focused(&self, id: WeakWidget<TextEdit>) -> bool {
+        self.default_state().focus == Some(id)
+    }
+
+    fn focus_gained(&mut self, region: Option<PixelRegion>) {
+        let state = self.default_state_mut();
+        let Some(region) = region else { return };
         state.window.set_ime_allowed(true);
+        // Physical, like everything else this backend hands winit --
+        // `default::content_scale`.
         state.window.set_ime_cursor_area(
-            LogicalPosition::<f32>::from(region.top_left.tuple()),
-            LogicalSize::<f32>::from(region.size().tuple()),
+            PhysicalPosition::<f32>::from(region.top_left.tuple()),
+            PhysicalSize::<f32>::from(region.size().tuple()),
         );
     }
-    state.focus = Some(id);
 }