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>

docs/DECISIONS.md

@@ -5,6 +5,30 @@ they can be judged and reversed later. Detail lives in RUST.md (and IRIS.md
 for iris API changes); this file is only the summary. Newest first. Items
 marked **DEFERRED** are ones the agent chose not to decide alone.
 
+## 2026-09-08 (the port is one crate, and iris is framework-only)
+
+Asked for by Iris directly, so the shape rather than the fact is what is
+open to review. `app-rust/` is one crate, `ai-app`, with `client`, `ui`,
+`desktop`, `android` and `shell` as modules; `iris/` holds only `core`,
+`macro`, `iris`, `tabs-ui` and `rig-input`. docs/RUST.md's "One app crate"
+has the table and the reason each old split did or did not survive.
+
+Three calls made inside that, none of which she named:
+
+1. **`event-model` stayed at the repo root** rather than moving into
+   `app-rust/` -- her choice when asked, since `server/` depends on it too.
+2. **The Android application id and Java package were left alone**
+   (`dev.iris.android.demo`, label "iris android-view demo"), though both
+   now name the wrong thing. Renaming them makes the next install
+   side-by-side rather than an upgrade on her phone, and changes the
+   `DevLogProvider` authority Dev Updater reads. Say the word and it is a
+   small change.
+3. **The `bench` fixture is behind a `fixture` feature that is on by
+   default**, with `build-apk.sh` passing `--no-default-features` so an APK
+   carries the 1.9 MB fixture only when it asked for `bench`. The
+   alternative -- default off -- would have made `cargo test` silently skip
+   the six harness suites, which is the worse failure.
+
 ## 2026-09-08 (last: scrolling moves out of the list)
 
 Agreed with Iris in the exchange that followed, so most of this is her