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>

run-tests.sh

@@ -1,18 +1,25 @@
 #!/bin/sh
-# Runs this repo's tests. Extra arguments are forwarded to each `cargo test`,
-# e.g. `./run-tests.sh transcript` to run just the transcript tests in all
-# three crates.
+# Runs this repo's Rust tests. Extra arguments are forwarded to each
+# `cargo test`, e.g. `./run-tests.sh transcript` to run just the transcript
+# tests in every workspace.
 #
-# server/ holds the backend's own logic (event normalization, transcript
-# cursors, config persistence, token auth); event-model is the wire shape
-# server/ and client-core share; client-core is the app's pure logic held
-# once instead of twice (see CLIENT_CORE.md) -- the syntax highlighter, the
-# ANSI parser, the transcript cache and fold, the REST and SSE clients. It
-# is not wired into the Android app yet (RUST.md), which still carries its
-# own Kotlin copies and has no tests of its own to run here; verifying it
-# means running it -- see AGENTS.md.
+# Three workspaces, in dependency order:
+#
+#   event-model  the wire shape server/ and app-rust/ share, so the two
+#                agree by construction rather than by review
+#   server/      the backend's own logic (event normalization, transcript
+#                cursors, config persistence, token auth)
+#   app-rust/    the app itself: `client` (highlighter, ANSI parser,
+#                transcript cache and fold, REST and SSE clients -- see
+#                docs/CLIENT_CORE.md) and `ui` (the screens, drawn with
+#                iris), plus the headless harness tests over the bench
+#                fixture that need no window and no GPU.
+#
+# `iris/` is the UI framework and has its own tests; run them from there
+# (`cd iris && cargo test`). They are not in this loop because iris is not
+# about this product and its suite is the slower of the two.
 set -eu
 cd "$(dirname "$0")"
-for crate in event-model client-core server; do
-  (cd "$crate" && cargo test "$@")
+for workspace in event-model server app-rust; do
+  (cd "$workspace" && cargo test "$@")
 done