Prune the docs of work already done: 18,252 -> 7,567 lines

Iris: "the documentation is also pretty crazy too. Can you go through it
and remove everything that's already done and decided? There's entire md
files iirc for projects already complete. And many with checkboxes already
ticked off that just fill up context."

  docs/RUST.md        8503 -> 905    the framework bake-off (options,
                                     recommendation, twelve closed
                                     experiment boxes) and two superseded
                                     "where things stand" sections, out;
                                     what the experiments settled kept as
                                     one line each
  docs/IRIS_TODO.md   1383 -> 229    fifty closed items and six
                                     phone-report sections whose defects
                                     are all fixed
  docs/LAYOUT.md      1116 -> 829    the pre-implementation framing: the
                                     old trait, the checklist, the
                                     migration list, the pass conditions
  docs/TEXTURES.md     496 -> 240    the prior-art survey, the proposal
                                     and its review, all implemented
  docs/REVIEW-*.md     673 -> 0      two completed review passes; the two
                                     findings left open on purpose (mask
                                     hit-testing, the phone's font set)
                                     moved into RUST.md

What survives a prune is what cannot be cheaply re-derived: measurements
(the APK-size table, the phone bench reports), dead ends, invariants and
their reasons, and the design of what exists now rather than the route to
it. AGENTS.md now says that, so the next session prunes as it goes rather
than appending; docs/IRIS_TODO.md's header says items are deleted when
they land rather than ticked.

Deleting the two review files left eighteen citations dangling in code
comments that state their reason inline and cited the file for provenance
only — those now read "(review, 2026-09-06)" and carry no dead pointer.
The emulator's measured GPU capabilities moved to the this-machine-android
skill, where machine facts belong. IRIS.md and DECISIONS.md are dated
records and were not rewritten; each gained one note that paths in older
entries predate the 2026-09-08 crate merge, pointing at the mapping.

Not touched, deliberately: docs/DECISIONS.md's entries (that file *is* the
queue of things for Iris to review, so deleting decided items would remove
what it exists for) and iris/readme.md and iris/TODO, which are hers.

Verified: ./run-tests.sh and `cd iris && cargo test` green, clippy and fmt
clean in every workspace, and every remaining docs/*.md cross-reference
resolves.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

app-rust/src/android/bench_client.rs

@@ -196,8 +196,8 @@ fn battery_line(samples: &[i32]) -> String {
     // up -- pairing the `Option` unwraps with the emptiness check right
     // here (rather than two statements apart, with `mean` in between
     // reading the same slice) is what keeps a future reorder from
-    // separating the guard from what it protects (docs/
-    // REVIEW-2026-09-06.md finding 7).
+    // separating the guard from what it protects (review, 2026-09-06
+    // finding 7).
     let (Some(min), Some(max)) = (samples.iter().min(), samples.iter().max()) else {
         unreachable!("samples is non-empty, checked above");
     };

app-rust/src/ui/mod.rs

@@ -292,7 +292,7 @@ impl TranscriptScreen {
                 // rebuild with *fewer* blocks under the same key would
                 // otherwise leave the extra blocks in `Selection`
                 // pointing at widgets the `drop` below frees (the shape
-                // docs/REVIEW-2026-09-06.md's finding 1 called out).
+                // a review on 2026-09-06 called out).
                 self.selection.borrow_mut().unregister(old_key);
                 // Uncapped: this is the row a delta just failed to land
                 // in, and the reason may be that it *is* capped
@@ -319,7 +319,7 @@ impl TranscriptScreen {
                 // gets cleared the same way `LazySpan` does, right before the
                 // rows it was pointing at go with it -- `push_row` below
                 // re-`register`s whatever survives as it rebuilds each
-                // row (docs/REVIEW-2026-09-06.md finding 1: a key that
+                // row (review, 2026-09-06 finding 1: a key that
                 // `group_tool_runs` regrouped away used to stay in
                 // `Selection` pointing at a widget this `clear()` had
                 // just freed, panicking the next long-press anywhere).
@@ -623,7 +623,7 @@ mod diff_tests {
 }
 
 /// Exercises `TranscriptScreen::apply`'s `Rebuild` arm through a real
-/// `Selection`, the gap docs/REVIEW-2026-09-06.md finding 8 named: the
+/// `Selection`, the gap the 2026-09-06 review named: the
 /// pure `diff_rows` decision above and `selection.rs`'s own registration
 /// tests each pass in isolation, and neither alone catches finding 1 (a
 /// regrouped-away row's key surviving in `Selection` after `LazySpan::clear()`

app-rust/src/ui/selection.rs

@@ -105,7 +105,7 @@ impl Selection {
     /// clears the list, and what `TranscriptScreen::apply`'s `Rebuild` arm
     /// calls right before it, since a full rebuild drops every row's old
     /// widget and `push_row` re-`register`s each surviving key's new one
-    /// as it goes (review docs/REVIEW-2026-09-06.md finding 1: the
+    /// as it goes (review, 2026-09-06 finding 1: the
     /// `Rebuild` arm used to call only `LazySpan::clear()`, leaving any key
     /// dropped by the regroup -- present in the old rows, absent from the
     /// new ones -- pointing at a widget the list had just freed, so the
@@ -350,8 +350,7 @@ impl Selection {
                 // Only when `fling` actually took it: below Compose's
                 // `|v| <= 1.0` there is nothing to tick, and registering
                 // an animation for a widget that is not animating asks the
-                // next frame to find that out (docs/REVIEW-2026-09-07.md's
-                // second nit).
+                // next frame to find that out (review, 2026-09-07).
                 if let Some(scroll) = self.scroll
                     && scroll(ui).fling(v)
                 {

app-rust/tests/input_log_roundtrip.rs

@@ -2,7 +2,7 @@
 //! themselves rather than a widget: `iris::diagnostics::set_trace` gates
 //! `iris::input`/`iris::frame` (Iris's 2026-09-07 request, "add another
 //! button to copy input event info ... instrument a lot of the code with
-//! timings"), and `docs/REVIEW-2026-09-07.md`'s D1 found that the switch
+//! timings"), and the 2026-09-07 review found that the switch
 //! existed but four older per-frame `debug!` lines were not wired to it,
 //! filling the app's 2000-line log ring with frame spam before `Copy
 //! report` had a chance to include anything else. This is what a fix to

app-rust/tests/phone_screen.rs

@@ -71,7 +71,7 @@ fn a_recorded_flick_releases_with_a_velocity_and_flings_the_list() {
     // found in the spline's own tests, and it left this one able to fail
     // in the "ran too long" direction only -- never in the "stopped dead"
     // direction, which is what Iris actually reported
-    // (docs/REVIEW-2026-09-07.md's T1).
+    // (review, 2026-09-07's T1).
     const REFERENCE_MS: u64 = 2071;
     const REFERENCE_PX: f32 = 11057.0;
     let end = flick.end_ms() + REFERENCE_MS * 2;

app-rust/tests/top_edge.rs

@@ -138,7 +138,7 @@ fn the_list_is_clipped_to_its_own_box() {
     // mask exists and sits in the right place; neither says any primitive
     // references it, so a broken `Mask::parent` chain -- what d507ae4
     // introduced -- would leave them green while a code fence inside a row
-    // drew unclipped again (docs/REVIEW-2026-09-07.md's T3).
+    // drew unclipped again (review, 2026-09-07's T3).
     let rows = h
         .render
         .active
@@ -213,7 +213,7 @@ fn mask_chain(h: &Harness, mask: MaskIdx) -> Vec<MaskIdx> {
 /// every height already known -- including the second walk *back*, which
 /// is there because a regression that draws rows in the wrong place while
 /// travelling backwards would otherwise be checked only by the row count
-/// (docs/REVIEW-2026-09-07.md's T2). That is also the ordinary state of a
+/// (review, 2026-09-07's T2). That is also the ordinary state of a
 /// transcript being panned around in. The bound on how many rows are
 /// placed at once holds on all three.
 #[test]