M4: a letter and its combining marks shape with one font (#1478) (#1532)

* M4: a letter and its combining marks shape with one font (#1478)

* M4: the stacked-mark test checks positions only in fonts whose anchors stack them (#1478)

* M4: the cluster face rule is tested with stand-in faces, so it runs without system fonts (#1478)

* M4: the #1478 tests use stand-in faces only, so they run everywhere

docs/roadmap.md

@@ -1,6 +1,6 @@
 # FigCraft roadmap: milestones and what's next
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-28 · **Change:** minor (comment.list reports each message's @mentions (#1415); M8: mask groups draw only over the area they can paint, and nested isolated layers share one memory budget (#1061); M2: components can't contain their own instances, directly or through others; `edit.duplicate` returns an id map with `map: true` (#995); the batches kept for reconnecting apps are bounded in bytes by default, and `figcraft-server` takes `max_log_mb` (#1069); MCP and control calls name their document (#998); sibling placement in live sessions searches instead of counting (#1065); an AI agent attached over MCP comments under its own name, with an Agent label (#1414); the instance-swap menus have a search field (#1338); a refused batch's fixes take time linear in the batch (#1063); the connector tool shows the connector it will make while dragging, ends snapping to attach points (#1387); large images on the canvas draw from a smaller copy, so two 16k images no longer lag (#1483); a file's JPEG thumbnail can't crash the home screen (#1491's progressive JPEG check, now shared); `.fig` import: library text styles linked by asset key, and override rows restating a nested level (#1234); `.fig` import keeps the file's saved line breaks while the text and its box are unedited (#1236); Download a missing free font from the Missing fonts window (`font.download`, #754); the web build's wasm back under its 24 MiB gate (#1472); shadows of images with transparent pixels follow their alpha (#1289); Crop image: Object ▸ Crop image, the right-click menu and the image fill row enter crop mode (`image.crop`, #1464); M0.9: optional batch continue-on-error with per-step outcomes (#1386); Alt pressed during a drag duplicates (#1385); variables in paint props (M3, #1000); finding layers without selecting them (M0.9, part of #996); the attached MCP server reads the app's replies with a 512 MiB bound (#1113); a failed batch keeps the undo steps it undid (#1410); Arabic draft catalog; Android Vector Drawable export; a selected unfilled shape drags over a filled layer below it (#1370); text truncation fills the last line, survives resizing, and auto height takes Max lines (#1375, #1376, #1377); M11 widget fields and property menus; M12 Boards: timer and voting; Installed weights of an embedded font family (#1246); `.sketch` import, best effort; Adobe Fonts found on macOS (#298); M12 Boards; community fixes in #507, #510, #529 and #530: auto-save, a text box by dragging, batch step references, removing someone from a live session, Russian and Turkish catalogs reviewed, Czech and Indonesian drafts, the Japanese draft completed, zoom previews, the web clipboard, Alt-drag snapping and Cmd+D repeat, recovery copies, crash and rollback fixes, colour emoji, `.fig` import fixes; earlier changes are in the revision history below) · **Target:** Figma Design (desktop app 126.10.7)
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-28 · **Change:** minor (Vietnamese letters typed with combining marks (decomposed) take one font that has every mark, instead of missing-glyph boxes beside the letter (#1478); comment.list reports each message's @mentions (#1415); M8: mask groups draw only over the area they can paint, and nested isolated layers share one memory budget (#1061); M2: components can't contain their own instances, directly or through others; `edit.duplicate` returns an id map with `map: true` (#995); the batches kept for reconnecting apps are bounded in bytes by default, and `figcraft-server` takes `max_log_mb` (#1069); MCP and control calls name their document (#998); sibling placement in live sessions searches instead of counting (#1065); an AI agent attached over MCP comments under its own name, with an Agent label (#1414); the instance-swap menus have a search field (#1338); a refused batch's fixes take time linear in the batch (#1063); the connector tool shows the connector it will make while dragging, ends snapping to attach points (#1387); large images on the canvas draw from a smaller copy, so two 16k images no longer lag (#1483); a file's JPEG thumbnail can't crash the home screen (#1491's progressive JPEG check, now shared); `.fig` import: library text styles linked by asset key, and override rows restating a nested level (#1234); `.fig` import keeps the file's saved line breaks while the text and its box are unedited (#1236); Download a missing free font from the Missing fonts window (`font.download`, #754); the web build's wasm back under its 24 MiB gate (#1472); shadows of images with transparent pixels follow their alpha (#1289); Crop image: Object ▸ Crop image, the right-click menu and the image fill row enter crop mode (`image.crop`, #1464); M0.9: optional batch continue-on-error with per-step outcomes (#1386); Alt pressed during a drag duplicates (#1385); variables in paint props (M3, #1000); finding layers without selecting them (M0.9, part of #996); the attached MCP server reads the app's replies with a 512 MiB bound (#1113); a failed batch keeps the undo steps it undid (#1410); Arabic draft catalog; Android Vector Drawable export; a selected unfilled shape drags over a filled layer below it (#1370); text truncation fills the last line, survives resizing, and auto height takes Max lines (#1375, #1376, #1377); M11 widget fields and property menus; M12 Boards: timer and voting; Installed weights of an embedded font family (#1246); `.sketch` import, best effort; Adobe Fonts found on macOS (#298); M12 Boards; community fixes in #507, #510, #529 and #530: auto-save, a text box by dragging, batch step references, removing someone from a live session, Russian and Turkish catalogs reviewed, Czech and Indonesian drafts, the Japanese draft completed, zoom previews, the web clipboard, Alt-drag snapping and Cmd+D repeat, recovery copies, crash and rollback fixes, colour emoji, `.fig` import fixes; earlier changes are in the revision history below) · **Target:** Figma Design (desktop app 126.10.7)
 
 Forward-looking plan. Where FigCraft stands today: [`ROADMAP.md`](../ROADMAP.md) and
 [`target-app-parity.md`](target-app-parity.md); the full ranked list: [`gaps.md`](gaps.md). Hours
@@ -75,6 +75,7 @@ blockers.
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-29 | patch | M4, #1478: a letter and its combining marks are shaped with one font that has them all. Text typed decomposed (NFD, `E` + U+0302 + U+0309 for Ể) in a font with the letters but not the marks drew missing-glyph boxes beside and above the letter, while the precomposed form fell back to a font that has it; each grapheme cluster now takes the first face (the style's own, then the fallbacks) that covers every char in it (joiners and variation selectors need no glyph), else the letter's own face as before. Fonts that cover Vietnamese were already right: mark positioning (GPOS `mark`/`mkmk`) stacks the marks over the letter on the canvas, in PNG, SVG and PDF. Tests in `crates/text/src/vietnamese_tests.rs`. Numbers unchanged |
 | 2026-10-29 | minor | M9, #1415: `comment.list` (CLI, MCP `run_command`, the `figcraft://comments` resource) gives every message, the first and each reply, its `mentions`: `{name, known, you}` for each name it @mentions, by the rule the thread view highlights them with (`figcraft_doc::mentions`, which the highlighting now shares). A name resolves against the file's people and you, as the file spells it. An unknown name is reported with `known: false`. `a@b.com` mentions nobody. Filtering threads by a mentioned name and listing mentioned names in `comment.people` stay open. Numbers unchanged |
 | 2026-10-29 | minor | M8, #1061: a mask group's pixmaps cover only where its mask or content can paint within the view (a 40 × 40 mask on a 3000 × 2000 view: 96 MB → 61.5 kB, same pixels), and isolated layers share a 2 GiB budget held at once per render thread; a layer past it is left out with a warning. Tests: `mask_bounds_tests` |
 | 2026-10-29 | minor | M2, #1084: a component can't contain its own instance, directly or through other components (each variant counts as its own component, so a variant may hold a sibling variant's instance unless that one leads back to it). Edits that would close such a loop are refused with it named, a file holding one opens with an instance detached and a note, and a rebuild never expands an instance inside a copy of itself (a loop merged in a live session stops growing). Tests: `component_cycle_tests` |

docs/target-app-parity.md

@@ -296,7 +296,8 @@ Hours in this narrative are the builders' estimates; the tables above supersede
    decorations from the font's metrics; CJK line breaking (between ideographs, kana and Hangul, no
    break inside Latin words, kinsoku to JIS X 4051 for closing and opening punctuation, small kana
    (halfwidth too), the prolonged sound mark, the iteration marks, the (semi-)voiced sound marks
-   and the halfwidth parentheses); a style's metrics from its own font, not a fallback; carets, Delete and
+   and the halfwidth parentheses); a style's metrics from its own font, not a fallback; a letter and
+   its combining marks (Vietnamese typed decomposed, say) from one font that has them all; carets, Delete and
    Backspace by grapheme cluster; double-click and word moves by script run; IME composition with
    CJK; vertical trim (cap height to baseline). The tail suite (`crates/text/src/tail_tests.rs`,
    `crates/engine/src/text_tail_tests.rs`): lists per paragraph, nested up to 8 levels with Tab and