harness: ✎ (U+270E) tofus in rich markdown, code fences, and the queue-row button

[btipling]

Summary

U+270E ✎ (LOWER RIGHT PENCIL) paints as tofu in the Wasm harness. It must render on all three product surfaces — not just the queue-row button:

Surface	Path today	Why it tofus
Queue-row ✎ button	queue_band.zig dvui.button + composerIconFont() → DejaVu-only	Widget may not honor .font; if it falls through to mixed/faceFor, emoji wins
Rich markdown (paragraph / emphasis / headings)	paint_text.zig → addTextMixed(…, body)	faceFor(0x270E) == .emoji via isEmojiRelated 0x2600…0x2712. OpenMoji subset does not ship U+270E (it has ✏ U+270F). .notdef
Code / fence / inline code	paint_code.zig / fence runs → addTextMixed(…, .theme(.mono))	Same faceFor → OpenMoji. Vera does not have U+270E either. A mono-only path (no mixed) would also tofu

dvui has no per-glyph fallback. One wrong faceFor hits body and mono because both go through addTextMixed.

Shipped as the queue edit mark in #666. Operators also paste ✎ into prompts / model output / fenced snippets.

Coverage (locked)

• ✎ in a normal assistant/user paragraph is a pencil, not tofu
• ✎ inside a fenced code block / inline code is a pencil, not tofu (DejaVu at mono size, same as arrows in fences)
• Queue-row 40 px ✎ button is a pencil, not tofu
• Copy / ring bytes stay U+270E (paint-only face switch; no lookalike rewrite)

Grounded facts

Face	U+270E
DejaVu symbols subset	yes
Noto Sans Regular	no
OpenMoji subset	no (has U+270F ✏)
Vera Mono	no

unicode_face.zig: isEmojiRelated includes 0x2600…0x2712. That range already had ✓/✗ (U+2713 / U+2717) carved out for the same reason — OpenMoji claimed the block and did not ship the glyph. U+270E is still inside the emoji span.

addTextMixed (.symbols): paints fontSymbols() at base.size — so base = mono already sizes DejaVu to the fence. No new paint helper. Routing is the bug.

Suggested fix (not locked — direction)

Carve U+270E out of isEmojiRelated (same pattern as 0x2713 / 0x2717 in the 0x2600…0x2712 hole) so faceFor(0x270E) == .symbols. That one change is what rich markdown and code blocks need.

Queue button: keep pinning composerIconFont() (DejaVu). After the carve-out, a mixed fallthrough also works.

Do not switch the product glyph to ✏ U+270F unless every path is the emoji face — DejaVu has both, OpenMoji only 270F, and we are not rewriting operator/model text.

Tests

#	Case	Layer
1	faceFor(0x270E) == .symbols and !isEmojiRelated(0x270E)	unicode_face / test-rich
2	Neighbor dingbats that OpenMoji actually ships stay emoji (e.g. U+270F if still claimed, U+2764)	unit
3	Operator: paragraph containing ✎	harness preview
4	Operator: fenced block + inline `✎`	harness preview
5	Operator: queue-row ✎ button	harness preview

Related (same change, not a substitute)

Cancel "×" U+00D7 on the queue row also uses composerIconFont(). U+00D7 is in Noto, so the DejaVu subset excludes it → symbols-only button can tofu. Prefer ✕ U+2715 (in DejaVu) or the body face. Does not replace the U+270E contract above.

Non-goals

• Full Dingbats / color-emoji pencils
• Lookalike rewrite of U+270E in the ring
• harness: queue-row ✎ closes immediately; edit latch survives longer-session hydrate #676 edit-latch / blur-save

Docs

If the carve-out lands: one timeless sentence in docs/harness-limits.md / fonts/README.md (U+270E → DejaVu, including fences). No issue numbers.

Refs

• #666
• native/harness/src/rich/unicode_face.zig — isEmojiRelated / faceFor
• native/harness/src/rich/mixed_text.zig — addTextMixed symbols @ base.size
• native/harness/src/rich/paint_code.zig — fences / inline
• native/harness/src/ui/queue_band.zig — queue-row button
• native/harness/src/fonts/README.md

[btipling]

Plan: #679 — carve U+270E out of isEmojiRelated so rich markdown, fences, and the queue-row ✎ all paint DejaVu. Status DRAFT; next is plan-review.

[btipling]

Shipped on main via PR #681. Plan #679 already closed; this source was only Refs’d.

U+270E ✎ now routes to DejaVu (faceFor == .symbols) on markdown, fences, and the queue-row button.