Merge remote-tracking branch 'origin/rustify' into worktree-agent-a1ff0294b6c29127e

# Conflicts:
#	docs/RUST.md

docs/RUST.md

@@ -4561,6 +4561,26 @@ device.
       two-density crispness check IRIS_TODO.md's unit item asks for, and
       the two open items just above.
 
+      **Fling and jitter, 2026-09-06.** The two `IRIS_TODO.md` "From the
+      phone" items this box's own text names as follow-ups are fixed --
+      `List::fling`/`VelocityTracker`/`FlingCalculator` (IRIS.md's
+      2026-09-06 entry) and the `DragArbiter` slop-release jump (fixed by
+      applying only the excess past `DRAG_SLOP` on the crossing frame,
+      not the whole pre-threshold drag) -- both wired through
+      `Selection::drag`'s release path, both covered by new unit tests in
+      `iris/src/sense.rs` and `iris/src/widget/list.rs`. **Root-caused by
+      reading `DragArbiter::update` and testing it directly, not by an
+      emulator trace** -- this pass did not open an emulator, so the
+      "trace the list's offset per frame" verification this box's own
+      todo asked for is still open, as is a feel-check of the fling on
+      real touch input. **Benchmark v2's four-phase spec (fling/stream/
+      type/keyboard) in `bench_client.rs` was not attempted this pass** --
+      wiring a real IME show/hide and refresh-rate read through
+      `bench_jni.rs`, and `FrameReport`'s per-phase accounting, is real
+      scope on its own and was left rather than shipped half-verified;
+      the Compose half above is already done and is the reference shape
+      for whoever picks this up. No redelivery this pass.
+
 - [ ] **P1 — session screen parity.** History paging backward (with the
       page-boundary healing `client-core` does not have yet, below),
       `TranscriptSource`-backed cache/server stitching, jump-to-latest,