Exclude Fumadocs relative file links from lychee checking

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

lychee.toml

@@ -52,7 +52,11 @@ exclude = [
     "https://x.com*",
 
     # Email links
-    "mailto:*"
+    "mailto:*",
+    
+    # Fumadocs relative links (handled by framework at runtime)
+    # These are links like ./agent that resolve to .mdx files
+    "file://**/content/docs/**"
 ]
 
 # Cache results to speed up subsequent runs