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>

rig-input/Cargo.toml

@@ -0,0 +1,32 @@
+[package]
+name = "rig-input"
+version.workspace = true
+edition.workspace = true
+
+# Layer 2's input half (docs/RUST.md's "Three test layers"): replays one
+# of the `.touch` files the headless tests use into whatever window is
+# under a Wayland compositor, so the *same recording* drives the
+# assertion layer and the layer a person looks at.
+#
+# It exists because this machine's compositor has no pointer to move.
+# `run-headless.sh` starts sway on the headless backend with no input
+# devices at all (`WLR_LIBINPUT_NO_DEVICES=1`, `LIBSEAT_BACKEND=noop`),
+# so `swaymsg seat - cursor press` reports success and nothing reaches
+# the client -- `swaymsg -t get_seats` shows `capabilities: 0`. wlroots
+# 0.19 dropped `WLR_HEADLESS_INPUTS`, and ydotool's uinput device would
+# be ignored by a compositor that is not reading libinput. The
+# virtual-pointer protocol is what is left, and it is a client protocol,
+# so it needs no devices and no root.
+
+# Named for what it does rather than for the crate, since the crate may
+# grow a keyboard replay beside it.
+[[bin]]
+name = "replay-touch"
+path = "src/main.rs"
+
+[dependencies]
+# `TouchScript` -- the same parser the harness uses, so a file that
+# replays here and one that replays headless can never disagree.
+iris = { path = ".." }
+wayland-client = "0.31.15"
+wayland-protocols-wlr = { version = "0.3.12", features = ["client"] }