docs/RUST.md: P1 started on Iris's word, sub-order P1a-P1e by what makes the bench fair

docs/RUST.md

@@ -5374,7 +5374,54 @@ device.
       before/after screenshot pair for item 3 (blocked on item 2); anything
       on Vulkan or the real phone.
 
-- [ ] **P1 — session screen parity.** History paging backward (with the
+- [ ] **P1 — session screen parity.** **Started 2026-09-06, on Iris's
+      word**: "just continue with the plan for now; try to move towards
+      feature parity for the transcript screen so that the test can be
+      more fair." So P0's "must pass before P1 starts" is lifted — the
+      phone bench continues alongside, and parity is what makes its
+      comparison fair. **Sub-order, decided by the design agent, by what
+      the bench fixture exercises and Compose already draws** (each is
+      one agent; tick and date in place):
+      - [ ] **P1a — markdown block rendering parity.** Now that a row is
+            a column of per-block widgets (`e1030d6`), draw each block
+            the way Compose does: headings at their sizes, fences in a
+            mono face with `client-core`'s `highlight` spans and a
+            distinct background, bullet/numbered lists with indent,
+            tables as aligned columns, block quotes, links as tappable
+            spans (opening through the platform — the "tappable link"
+            primitive in IRIS_TODO's "Build (for the port)"). Against
+            `app/bench-fixture/`, screenshot beside the Compose bench
+            build on the same emulator. Pure parts (block → style
+            mapping) tested in `client-core`/`transcript-ui`.
+      - [ ] **P1b — tool-call cards and grouping.** `ToolRows.kt`/
+            `ToolInput.kt`'s cards: a collapsed row per call with name
+            and a one-line summary, expand to input and output, runs of
+            calls grouped (`adopt_run` already groups in `client-core`),
+            the busy/failed states, and the kilobyte outputs the fixture
+            carries without laying them out while collapsed.
+      - [ ] **P1c — history paging and jump-to-latest.** Wire
+            `client-core::transcript_source` into `transcript-ui`:
+            the opening page, paging back on scroll with the cushion
+            measured in on-screen viewports (`HISTORY_SCREENS`, IRIS_TODO
+            "Build (for the port)"), the `NothingLoaded`/empty/error
+            states drawn distinctly (UI_RULES: design the unknown state
+            first), `join_pages` at each seam, and a jump-to-latest
+            control that pins to the newest end. Pass condition: the
+            P1 pass condition below, against `ui-sandbox.sh` with
+            `AI_SANDBOX_BIG_MB` and `--delay`.
+      - [ ] **P1d — images, the session settings dialog, attachments,
+            usage bar.** `SessionImage` thumbnails (the scaled image
+            widget), the modal primitive and `SessionSettingsDialog`/
+            `UsageDialog`, `PendingAttachments` over the attachments
+            route (`api.rs` gap), `SessionUsageBar` (the gauge widget).
+      - [ ] **P1e — keyboard and insets behaviours** from AGENTS.md's
+            "Things that have bitten", re-verified on the phone build:
+            composer never left floating after the keyboard closes
+            mid-stream, `adjustResize` + edge-to-edge together, one
+            recomposition-equivalent per keyboard toggle (the
+            `iris insets:` log line count).
+
+      History paging backward (with the
       page-boundary healing `client-core` does not have yet, below),
       `TranscriptSource`-backed cache/server stitching, jump-to-latest,
       tool-call cards and grouping, the session settings dialog, composer