feat: convert broken wiki links to plain text instead of styled anchors

When disableBrokenWikilinks is enabled, wiki links to non-existent
pages now render as plain text rather than faded anchor tags.

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

quartz/plugins/transformers/ofm.ts

@@ -283,8 +283,8 @@ export const ObsidianFlavoredMarkdown: QuartzTransformerPlugin<Partial<Options>>
                   const exists = ctx.allSlugs && ctx.allSlugs.includes(slug)
                   if (!exists) {
                     return {
-                      type: "html",
-                      value: `<a class=\"internal broken\">${alias ?? fp}</a>`,
+                      type: "text",
+                      value: alias ?? fp,
                     }
                   }
                 }