Make the Rust client the sole app

app/bench-fixture/README.md

@@ -1,16 +1,13 @@
 # The P0 benchmark fixture
 
-`transcript.jsonl` is a synthetic transcript in the app's own event model (the JSON lines
-`GET /sessions/{id}/transcript` returns; see `Events.kt`'s `parseSeqEvent` and
-`server/src/session/driver.rs`) -- never a real one. It is what both the Compose `bench` build
-and iris's bench build open with no server, so the two apps draw exactly the same content and a
-frame-time comparison is measuring the renderer rather than the data.
+`transcript.jsonl` is a synthetic transcript in the app's event model (the JSON lines
+`GET /sessions/{id}/transcript` returns; see `event-model` and
+`server/src/session/driver.rs`) -- never a real one. The `bench` build opens it without a
+server so renderer measurements use deterministic data.
 
 Generated by `./generate.py` (Python stdlib only, seeded -- `SEED = 20260905` -- so re-running it
-reproduces the same file byte for byte). It writes into `assets/` -- a separate directory from this
-script and README, because the Compose `bench` build type points its own asset source set straight
-at `assets/` (`app/androidApp/build.gradle.kts`'s `sourceSets { getByName("bench") }`), and a Python
-script and a markdown file have no business inside an APK:
+reproduces the same file byte for byte). It writes into `assets/`; only those generated assets are
+embedded in the benchmark APK.
 
 - `transcript.jsonl` -- 3,603 events. The first 3,202 (`BACKLOG_COUNT`) are the scrolled-back
   history the benchmark opens with: user turns, tool calls with kilobyte-scale input/output,
@@ -31,7 +28,7 @@ script and a markdown file have no business inside an APK:
   **The run-on message is kept**, as the first two events of the backlog: 14,824 characters in a
   single block, just under `text_cap`'s 16 KiB `MESSAGE_BYTES` so it draws in full rather than
   behind a "Show all". It is deliberately *not* streamed -- the repeated-reshape pathology needs a
-  growing block, and that lives in `app-rust/tests/frame_profile.rs` where it can be iterated on
+  growing block, and that lives in the UI profiling rig where it can be iterated on
   in a second rather than in a two-minute phone run. It is emitted with the random state saved and
   restored around it, so adding it left every other backlog event byte-identical; that is what
   keeps `phone_screen.rs`'s recorded gestures landing on the content they were recorded against.
@@ -39,10 +36,9 @@ script and a markdown file have no business inside an APK:
   same way a real attachment is (`GET /sessions/{id}/files/{name}`), referenced by the two
   `"type":"image"` events in the transcript.
 
-`BACKLOG_COUNT` lives in three places and moves in all of them or none: here, `app-rust/src/ui/
-fixture.rs` and `BenchFixture.kt`. The split is by line index, so a stale copy makes that app open
-a different half of the file.
+`BACKLOG_COUNT` lives here, in `generate.py`, and in `app/src/ui/fixture.rs`; change all three
+together. The split is by line index.
 
 Regenerate after changing the shape (a new event type, a different backlog/stream split) with
 `./generate.py`, and commit the result -- it is checked in rather than generated at build time so
-both apps' bench builds embed the identical bytes without needing this script at build time.
+the benchmark embeds identical bytes without needing this script at build time.