claude: fix relative font-paths in typst extensions (#13745)

Only resolve font paths that come from extensions (paths containing
_extensions or starting with ..) relative to the input directory.
Other relative paths like .quarto/typst-font-cache should remain
relative to the working directory where typst runs.

This fixes the issue where font-paths specified in extension
configurations weren't being found when the input document was in
a subdirectory, while preserving correct behavior for brand font
cache paths.

Adds a test case that verifies extension font-paths work correctly
when the document is in a subdirectory.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: gordonwoodhull

news/changelog-1.9.md

@@ -41,6 +41,7 @@ All changes included in 1.9:
 - ([#13555](https://github.com/quarto-dev/quarto-cli/issues/13555)): Add support for `icon=false` in callouts when used in `format: typst`.
 - ([#13589](https://github.com/quarto-dev/quarto-cli/issues/13589)): Fix callouts with invalid ID prefixes crashing with "attempt to index a nil value". Callouts with unknown reference types now render as non-crossreferenceable callouts with a warning, ignoring the invalid ID.
 - ([#13602](https://github.com/quarto-dev/quarto-cli/issues/13602)): Fix support for multiple files set in `bibliography` field in `biblio.typ` template partial.
+- ([#13745](https://github.com/quarto-dev/quarto-cli/issues/13745)): Fix relative `font-paths` in custom Typst format extensions not working when the input document is in a subdirectory. Extension font paths are now resolved relative to the input file directory.
 - ([#13775](https://github.com/quarto-dev/quarto-cli/issues/13775)): Fix brand fonts not being applied when using `citeproc: true` with Typst format. Format detection now properly handles Pandoc format variants like `typst-citations`.
 - ([#13249](https://github.com/quarto-dev/quarto-cli/pull/13249)): Update to Pandoc's Typst template following Pandoc 3.8.3 and Typst 0.14.2 support:
   - Code syntax highlighting now uses Skylighting by default.

src/command/render/output-typst.ts

@@ -69,11 +69,22 @@ export function typstPdfOutputRecipe(
     // run typst
     await validateRequiredTypstVersion();
     const pdfOutput = join(inputDir, inputStem + ".pdf");
-    // Resolve font paths to absolute paths since typst compile may run from
-    // a different working directory than the input file's directory
+    // Resolve extension font paths to absolute paths since typst compile runs
+    // from the project root, not the input file's directory. Extension paths
+    // (containing _extensions or starting with ..) need resolution relative to
+    // inputDir, while other paths (like .quarto/font-cache) should remain
+    // relative to the working directory.
     const fontPaths = asArray(format.metadata?.[kFontPaths]).map((p) => {
       const fontPath = p as string;
-      return isAbsolute(fontPath) ? fontPath : join(inputDir, fontPath);
+      if (isAbsolute(fontPath)) {
+        return fontPath;
+      }
+      // Extension-resolved paths need to be resolved relative to input file
+      if (fontPath.includes("_extensions") || fontPath.startsWith("..")) {
+        return join(inputDir, fontPath);
+      }
+      // Other relative paths (like .quarto/...) stay relative to working dir
+      return fontPath;
     });
     const typstOptions: TypstCompileOptions = {
       quiet: options.flags?.quiet,