docs: tick the drawn chevron

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

docs/IRIS_TODO.md

@@ -819,7 +819,11 @@ has the fuller account.
   nothing on screen says it was cut. Whichever end is cut has to be a
   choice when this lands: a path is identified by its tail, a command by
   its head.
-- [ ] **A drawn chevron.** *Still open, and now worse: the bundled fonts
+- [x] **A drawn chevron.** **Done 2026-09-08**: `iris::widget::mark(dir,
+  dp, colour)` rasterises an antialiased triangle into the ordinary
+  texture path and scales it into the box asked for, so no line/path
+  primitive was needed after all. `tool.rs` uses it for all three marks.
+  The original entry, for the record: *the bundled fonts
   were removed on 2026-09-07 in favour of the platform collection, so the
   mark is a codepoint the phone's own faces may not have -- Iris's
   2026-09-08 screenshot shows an empty box where it should be, and the

docs/RUST.md

@@ -8019,12 +8019,15 @@ framework and by looking at the fixture running
   shaped-mask work (`.masked_by`, 38bf630). `raw_block` pans sideways
   again instead of clipping, so a long command is readable. Ticked there
   with the original symptom kept.
-- **Still open, and the one certain thing in her screenshot**: the
+- **The one certain thing in her screenshot, now fixed**: the chevron.
-  chevron. The mark is a font codepoint (U+25B8/25BE/25B4) and the
+  The mark was a font codepoint (U+25B8/25BE/25B4) and the bundled fonts
-  bundled fonts were removed on 2026-09-07, so the phone draws an empty
+  were removed on 2026-09-07, so the phone drew an empty box and the
-  box and the desktop draws a dot. It needs a drawn mark -- a texture
+  desktop a dot. `iris::widget::mark(dir, dp, colour)` draws it instead:
-  generated at the size wanted, since iris has rects, text and textures
+  one oversampled, antialiased triangle rasterised into the ordinary
-  and no path primitive. Not done here.
+  texture path and scaled into the box asked for, so iris needed no new
+  primitive. Seen working in the phone-sized render (a real ▶ beside
+  "Edit"), and its two tests check it points the right way and leaves its
+  corners clear.
 
 ### 3. "The benchmark scrolling seems like it's at 60fps or something, it's
 ### way less smooth than me scrolling manually"