Fix second audit findings and restore crash detection dialog

src/core/footprint.rs

@@ -396,8 +396,14 @@ pub fn dir_size_pub(path: &Path) -> u64 {
 }
 
 fn dir_size(path: &Path) -> u64 {
-    if path.is_file() {
-        return path.metadata().map(|m| m.len()).unwrap_or(0);
+    // Use symlink_metadata to avoid following symlinks outside the tree
+    if let Ok(meta) = path.symlink_metadata() {
+        if meta.is_file() {
+            return meta.len();
+        }
+        if meta.is_symlink() {
+            return 0;
+        }
     }
     let mut total = 0u64;
     if let Ok(entries) = std::fs::read_dir(path) {
@@ -406,6 +412,10 @@ fn dir_size(path: &Path) -> u64 {
                 Ok(ft) => ft,
                 Err(_) => continue,
             };
+            // Skip symlinks to avoid counting external files or recursing out of tree
+            if ft.is_symlink() {
+                continue;
+            }
             if ft.is_file() {
                 total += entry.metadata().map(|m| m.len()).unwrap_or(0);
             } else if ft.is_dir() {