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>

xtask/src/apk.rs

@@ -8,7 +8,7 @@
 //! the Keystore-sealed enrollment, RUST.md's E3 entry explains why that
 //! code is reused rather than re-derived in Rust) and on
 //! `androidx.core:core-ktx` (used at runtime through JNI by
-//! `android-shell`'s `notify.rs`, for `NotificationCompat` and friends).
+//! the shell bridge's `notify.rs`, for `NotificationCompat` and friends).
 //! Both are ordinary Maven/AAR dependency graphs, and reimplementing a
 //! dependency resolver to avoid one Gradle invocation was not a good trade
 //! against "smallest honest route" (RUST.md's E5 box) -- especially since
@@ -34,7 +34,10 @@ pub fn build(variant: Variant, abis: &[String]) -> Result<PathBuf, Fail> {
     let repo_root = repo_root()?;
     let app_dir = repo_root.join("app");
     let shell_app_dir = app_dir.join("shellApp");
-    let android_shell_dir = repo_root.join("android-shell");
+    // The JNI bridge is the `shell` feature of the one app crate now, not
+    // a crate of its own -- `--no-default-features` is what keeps iris,
+    // wgpu and parley out of a `.so` for an app that draws with Compose.
+    let app_crate_dir = repo_root.join("app-rust");
 
     let sdk = sdk::find()?;
     sdk::require_ndk_installed(&sdk.root)?;
@@ -49,8 +52,8 @@ pub fn build(variant: Variant, abis: &[String]) -> Result<PathBuf, Fail> {
         )
     })?;
 
-    println!("==> Building android-shell for {}", abis.join(", "));
-    build_native_libs(&android_shell_dir, &shell_app_dir, &sdk, abis)?;
+    println!("==> Building the shell JNI bridge for {}", abis.join(", "));
+    build_native_libs(&app_crate_dir, &shell_app_dir, &sdk, abis)?;
 
     println!("==> Resolving the runtime classpath (one Gradle call -- see apk.rs's module doc)");
     let classpath_jars = runtime_classpath_jars(&app_dir, &sdk)?;
@@ -159,7 +162,14 @@ fn build_native_libs(
     // segfaults this emulator's driver (RUST.md's E1 entry), and there is
     // no reason for this crate's debug build to be bigger or slower for a
     // signing choice that has nothing to do with it.
-    cmd.args(["build", "--release", "-p", "android-shell"]);
+    cmd.args([
+        "build",
+        "--release",
+        "--lib",
+        "--no-default-features",
+        "--features",
+        "shell",
+    ]);
     cmd.env("ANDROID_HOME", &sdk.root);
     cmd.env("ANDROID_SDK_ROOT", &sdk.root);
     run_checked(
@@ -395,7 +405,7 @@ fn merge(
         std::fs::remove_dir_all(&stage).ok();
     }
     for abi in abis {
-        let so_name = "libandroid_shell.so";
+        let so_name = "libai_app.so";
         let src = shell_app_dir
             .join("src/main/jniLibs")
             .join(abi)

xtask/src/main.rs

@@ -1,6 +1,6 @@
 //! `cargo xtask apk` -- E5 (RUST.md): packages `app/shellApp` into a
 //! signed, installable APK with no Gradle in the packaging step itself.
-//! `cargo ndk` cross-compiles `android-shell`; `javac`/`d8` turn its two
+//! `cargo ndk` cross-compiles the app crate's `shell` feature; `javac`/`d8` turn its two
 //! Java stub classes (plus the generated pinned-CA constant) into dex;
 //! `aapt2` compiles the manifest into `resources.arsc`; the dex and native
 //! libraries are merged into that base APK with `jar`; `zipalign` and