fix(skills): stage a preset's own fonts/ folder in every build-frame.mjs

[miga-heygen]

What

Every workflow's build-frame.mjs (faceless-explainer, pr-to-video, product-launch-video) now stages a frame preset's own fonts/ folder into assets/fonts/ and appends one @font-face block to frame.md, covering both font sources (captured brand files + preset files). The filename → face helpers move into a shared scripts/lib/font-faces.mjs, byte-identical across the three skills and consumed by both build-frame.mjs and captions.mjs.

Refs #3583 (the media-use font-resolver half of that issue stays open).

Supersedes #3950 — carries srikarsunchu's change with signed commits so it can merge under the repo's signed-commit ruleset, plus: repo-oxfmt formatting, captions.mjs now imports the shared font-faces library instead of a hand copy, overlapping-family test, isFile guard.

Why

code-editorial ships licensed WOFF2 files and its FRAME.md promises they are staged. Only the pr-to-video copy did so, with the six filenames hard-coded and a hard exit for any other preset shipping a fonts/ folder; the other two copies never read the folder. A frame worker following font_family_without_font_face then found no file behind the preset's families and fell back to a system stack.

How

• lib/font-faces.mjs (new, ×3 identical): FONT_FORMAT, normFontName, fontExtOf, fontWeightInfo, fontStyleOf, fontFamiliesNamed, rankFontFamilies (longest family key first — the one ranking the brand block, stagePresetFonts and captions.mjs all use), familyOfFaceFile, stageFontFile, stagePresetFonts.
• stagePresetFonts is directory-driven: each plain file (statSync(...).isFile() in a try/catch, so a subdirectory or dangling symlink named like a font cannot reach copyFileSync and throw EISDIR/ENOENT) is assigned to the longest family the remixed frame.md still names whose key its stem starts with (familyOfFaceFile; a brand renamed to "Garamond" does not claim EBGaramond-400.woff2); files matching no named family are reported as skipped ("matching no family frame.md names"); faces the brand already staged are not staged twice (stagedFaces is shared across both sources and keyed on family + numeric weight + style, so Inter-Regular.ttf from the capture and Inter-400.woff2 from the preset are one face — first source wins); staged bytes are refreshed from the source only for the preset's fonts/ folder (stageFontFile({ refresh: true }); a skills update may ship re-subsetted files), skipping only a self-copy, while a capture file never overwrites a file already at its staged path, so a hand-placed face in assets/fonts/ keeps winning over the download; OFL-*/LICENSE* texts travel with any staged face.
• build-frame.mjs: the brand block calls stageFontFile; the preset block calls stagePresetFonts; one ## Font loading (auto-generated) section lists both sources. The brand scan's "single family owns every file" shortcut now applies only to capture/assets/fonts (hash-named downloads); files already in assets/fonts/ follow the staged-name contract and are matched by family-key prefix, because a previous run may have put the preset's faces there and a rerun after brand tokens arrive must not relabel EB Garamond's bytes as the brand font. pr-to-video drops its hard-coded six-file list and the die() on a missing file — a preset folder is now read as-is, so a missing file simply is not staged (this is the intended change: the hard exit fired for any other preset shipping a fonts/ folder).
• captions.mjs (×3 identical): brandFontFaces imports weight/style/format/key helpers from ./lib/font-faces.mjs; the private weightOf/styleOf/fmtOf/norm copies are deleted. Behaviour unchanged (the old fmtOf "opentype" fallback was unreachable behind the extension gate).
• code-editorial/FRAME.md notes that families the brand remix replaced are skipped.
• Formatted with the repo-pinned oxfmt (bunx oxfmt --check passes on all changed .mjs); skills-manifest.json regenerated.

Tests

• build-frame-fonts.test.mjs (new, ×3; tmp dirs removed in test.after): staging by family/weight/style from a fake preset; remix-replaced family skipped; brand-staged face not re-staged from the preset; preset without fonts/ stages nothing; shipped code-editorial stages six faces + three OFL texts; fontFamiliesNamed, fontWeightInfo, stageFontFile units; overlapping families "Inter" + "Inter Tight" → InterTight-700.woff2 lands on "Inter Tight", Inter-400.woff2 on "Inter" (fails with the length sort reversed); directory entry / dangling symlink named like a font is neither staged nor a crash (fails with the isFile guard removed, EISDIR; fails with the try/catch removed, ENOENT); word-vs-numeric dedup across sources (OtherMono-Bold.woff2 captured + OtherMono-700.woff2 preset → one file, one rule; fails with the dedup keyed on the weight token); stale bytes refreshed by stageFontFile with refresh: true and left alone without it (fails with the flag ignored either way); capture keeps a staged file end-to-end (brand-grotesk-400.woff2 captured vs a pre-existing BrandGrotesk-400.woff2; fails with the capture source refreshing); preset refresh end-to-end on a rerun after the staged bytes went stale (fails with stagePresetFonts not passing the flag); hash-named capture file 19cfc7226ec3afaa-s.woff2 staged as the single brand family and two brand families told apart by substring on CDN-style names (both fail with the capture rule replaced by the staged-name prefix rule); rerun after brand tokens does not relabel staged preset faces (brand "Sans" vs staged AcmeSans-*; fails with the shortcut applied to assets/fonts or with substring matching); substring family ("Tight" owns neither Inter-400 nor InterTight-700); font-faces.mjs byte-identity across the three skills.
• captions.test.mjs (×3): style-token check now targets lib/font-faces.mjs, restores the negative "must not assert font-style:normal" check, and asserts captions.mjs imports its helpers from the library (replacing the import with a stub fails the round-trip tests).
• env -u NODE_ENV node --test "skills/**/*.test.mjs": 684/687 pass; the single failure (media-use/scripts/resolve.test.mjs) is a missing @hyperframes/parsers/dist build in a fresh clone and fails identically on main.
• bunx tsx scripts/lint-skills.ts clean; bunx oxlint 0 warnings on the 15 changed .mjs; bun packages/cli/scripts/gen-skills-manifest.ts --check in sync.

— Miga