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/lib.rs

@@ -1,24 +1,59 @@
 #![feature(unboxed_closures)]
 #![feature(fn_traits)]
-#![feature(gen_blocks)]
-#![feature(associated_type_defaults)]
+// Only `default::DefaultAppState::Event`'s default uses this; unused (and
+// warned about) on the android target, which has no such default.
+#![cfg_attr(not(target_os = "android"), feature(associated_type_defaults))]
 #![feature(unsize)]
 #![feature(option_into_flat_iter)]
 #![feature(async_fn_traits)]
 
+// Two windowing backends live side by side, chosen by target rather than by
+// feature flag: winit everywhere but Android, android-view on it. They are
+// mutually exclusive rather than both-compiled-in because winit's own
+// Android support pulls in `android-activity`, which needs one of its
+// `game-activity`/`native-activity` features selected -- exactly what
+// `iris-core` was kept free of, and android-view is the framework's own
+// answer to the same surface on that platform. See RUST.md's I2.
+#[cfg(target_os = "android")]
+pub mod android;
+#[cfg(not(target_os = "android"))]
 pub mod default;
+
+pub mod attr;
+pub mod diagnostics;
 pub mod event;
+pub mod harness;
+pub mod platform;
+pub mod sense;
+pub mod state;
+pub mod task;
 pub mod widget;
 
+#[cfg(test)]
+mod access_tests;
+#[cfg(test)]
+mod layout_tests;
+#[cfg(test)]
+mod sense_tests;
+
 pub use iris_core as core;
 pub use iris_macro as macros;
 
 pub mod prelude {
     use super::*;
+    #[cfg(target_os = "android")]
+    pub use android::*;
+    #[cfg(not(target_os = "android"))]
     pub use default::*;
+
+    pub use attr::*;
     pub use event::*;
     pub use iris_core::*;
     pub use iris_macro::*;
+    pub use platform::*;
+    pub use sense::*;
+    pub use state::*;
+    pub use task::*;
     pub use widget::*;
 
     pub use iris_core::util::Vec2;