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/SUBAGENTS_DECISIONS.md

@@ -0,0 +1,44 @@
+# Decisions awaiting review
+
+Choices made while working autonomously, for Bryan to keep or change. Each
+says what was picked and why; the detail is in the design doc it names.
+Delete an entry once it has been looked at.
+
+## Subagent views (2026-09-05, `SUBAGENTS.md`)
+
+Made on my own judgement, limited blast radius:
+
+1. **A subagent is a transcript, not a session.** It has no process,
+   controls or settings; it is addressed as `/sessions/{id}/subagents/{sub}`
+   and stored under the session's directory, so deleting the session takes
+   it. Alternative rejected: registering it as a session of its own, which
+   would give it a card in the main list and a driver that can do nothing.
+2. **Read-only view is the session screen minus its controls**, rather than
+   a second, simpler transcript screen. Keeps paging, caching, selection
+   and rendering in one place. Cost: a `readOnly` mode threaded through
+   `SessionScreen`.
+3. **The list only carries a count.** Each session row says how many
+   subagents it has; their titles and statuses are fetched when the card is
+   expanded. Keeps `GET /sessions` from reading every subagent transcript.
+   Consequence: an expanded card's statuses refresh with the list, not live.
+4. **Expanded/collapsed is remembered per session on the phone**, not on
+   the server. Collapsed by default, per the transcript convention that new
+   things arrive collapsed.
+5. **Subagents of imported sessions are not shown.** The import path still
+   skips `isSidechain` records; the CLI's own `subagents/agent-*.jsonl` files
+   are not read. Only subagents run while this backend was watching exist.
+6. **Echo grows `/subagent [n]`** as the test rig, so nothing here needs a
+   paid turn to exercise.
+
+Deferred, because they reach further than this feature:
+
+- **Live status on the list.** Whether the session list should follow a
+  stream at all (it refreshes on demand today) decides whether subagent
+  status can ever be live there. Not changed.
+- **Nested subagents.** A subagent's own Task calls are shown as tool calls
+  in its transcript and are not given transcripts of their own. Supporting
+  that is the same mechanism one level down, but the UI would need nested
+  expanders.
+
+- **The subagent status row says "context unknown".** Nothing measures a
+  subagent's context; the row could leave it out rather than admit it.