some changes

static/js/markdown.js

@@ -13,10 +13,25 @@ function escapeHtml(value) {
   return String(value).replace(/[&<>"']/g, c => ({ "&": "&amp;", "<": "&lt;", ">": "&gt;", '"': "&quot;", "'": "&#039;" }[c]));
 }
 
+const emoji = EMOJI_SHORTCODES;
+let markdownFiles = new Map();
+let markdownFileRoutes = new Map();
+
+function attachmentRoute(value) {
+  try {
+    const path = new URL(String(value || ""), location.origin).pathname;
+    return /^\/f\/[^/]+\/[^/]+$/.test(path) ? path : null;
+  } catch {
+    return null;
+  }
+}
+
 function safeUrl(value) {
-  const raw = String(value || "").trim();
+  let raw = String(value || "").trim();
   if (!raw || raw.startsWith("//")) return "#";
   if (raw.startsWith("#")) return escapeHtml(raw);
+  const route = attachmentRoute(raw);
+  if (route && markdownFileRoutes.has(route)) raw = markdownFileRoutes.get(route);
   try {
     const url = new URL(raw, location.origin);
     if (url.protocol === "mailto:") return escapeHtml(url.href);
@@ -27,16 +42,18 @@ function safeUrl(value) {
   }
 }
 
-const emoji = EMOJI_SHORTCODES;
-let markdownFiles = new Map();
-
 export function setMarkdownFiles(files) {
-  markdownFiles = new Map((Array.isArray(files) ? files : [])
+  const normalized = (Array.isArray(files) ? files : [])
     .filter(file => file && file.filename && file.url)
-    .map(file => [String(file.filename), {
+    .map(file => ({
+      filename: String(file.filename),
       url: String(file.url),
       mimeType: String(file.mime_type || ""),
-    }]));
+    }));
+  markdownFiles = new Map(normalized.map(file => [file.filename, file]));
+  markdownFileRoutes = new Map(normalized
+    .map(file => [attachmentRoute(file.url), file.url])
+    .filter(([route]) => route));
 }
 
 export function unresolvedMarkdownFileAliases(value) {