refactor(fonts): read font faces via pdf-codec's readFontFace

runtime/font-face.ts's hand-rolled sfnt 'name'/'OS/2'/'head' table
reader duplicated logic pdf-codec now exports directly (readFontFace,
FontFaceParseError, published in pdf-codec 1.11.0) -- deleted along with
its own test suite, since that coverage now lives in pdf-codec's own
repository against the same real font fixtures. loadProvidedFonts calls
pdf-codec's readFontFace directly rather than through documents.js: a
standalone font-file inspector has no source-document-extraction
analogue, which is documents.js's own stated font-resolution boundary,
so routing it through documents.js would work around that boundary
rather than respect it.

Author: Mearman

src/runtime/font-face.test.ts

@@ -1,16 +1,17 @@
 import { readFile } from 'node:fs/promises';
 import type { ProvidedFont } from 'documents.js';
-import { describeFontFace } from './font-face';
+// A deliberate exception to this repo's usual "everything pdf-codec-sourced comes through documents.js" pattern: readFontFace is a standalone font-FILE inspector, not source-document font extraction, which is documents.js's own stated boundary (see its README -- extractSourceFonts/extractSourceFontsForFormat cover extracting fonts a document already embeds, not describing an arbitrary font file). Imported directly from pdf-codec, a genuine direct dependency of this package now, rather than forcing a re-export into documents.js that would work around that boundary.
+import { readFontFace } from 'pdf-codec';
 
-// Reads each font file and pairs its bytes with the family/bold/italic triple the file itself declares (see font-face.ts), producing exactly the ProvidedFont shape documents.js's own conversion options and DocumentConverter port both take. Shared by the CLI's --font-file flag and the TUI's own font-file field so the two can never derive a face differently from the same file.
+// Reads each font file and pairs its bytes with the family/bold/italic triple the file itself declares (pdf-codec's own readFontFace, parsed from the font's own sfnt tables), producing exactly the ProvidedFont shape documents.js's own conversion options and DocumentConverter port both take. Shared by the CLI's --font-file flag and the TUI's own font-file field so the two can never derive a face differently from the same file.
 //
 // Read sequentially rather than through Promise.all: a caller passing several fonts and mistyping one wants the error to name that file, and a sequential loop reports the first bad path with nothing else in flight. Font files are a handful of small local reads, so there is no throughput case for the parallel form here.
 export async function loadProvidedFonts(paths: readonly string[], options?: { readonly signal?: AbortSignal }): Promise<ProvidedFont[]> {
   const fonts: ProvidedFont[] = [];
   for (const path of paths) {
     // Rewrapped through the constructor's ArrayLike overload for the same reason readInput does it (src/runtime/io.ts): ProvidedFont.bytes is Uint8Array<ArrayBuffer>, which a Buffer is not.
     const bytes = new Uint8Array(await readFile(path, { signal: options?.signal }));
-    const face = describeFontFace(bytes, path);
+    const face = readFontFace(bytes, path);
     fonts.push({ family: face.family, bold: face.bold, italic: face.italic, bytes });
   }
   return fonts;