fix(docs): tolerate cross-tree links from audit reports in strict mode

The audit reports under docs/audit/reports/release-*/ reference repo
source files (e.g. `[file.py:line](file.py:line)`) on purpose — they
are read with the repo open, not as standalone published pages. MkDocs
in strict mode treats those as unrecognized links and aborts the build.

Set `validation.links.unrecognized_links: info` so the warning still
prints but doesn't fail the build. Real broken doc links (anchors,
absolute paths) keep their existing levels.

Refs the doc deploy run that broke just after the v0.5.0 tag was pushed.

mkdocs.yml

@@ -76,6 +76,11 @@ validation:
     absolute_links: info
   links:
     absolute_links: info
+    # Audit reports (audit/reports/release-X.Y.Z/) reference repo source
+    # files (e.g. `[file.py:line](file.py:line)`) by design — they're read
+    # alongside the repo, not as standalone docs. Downgrade to info so
+    # strict-mode builds don't fail on these intentional cross-tree links.
+    unrecognized_links: info
 
 markdown_extensions:
   - admonition