fix: skip corrupt/unreadable images instead of aborting scan

- scan_images now warns and continues on decode errors
- new test: scan_skips_corrupt_image_files
- 21 tests passing

src/lib.rs

@@ -40,9 +40,21 @@ pub fn scan_images(root: &Path) -> Result<Vec<ImageEntry>> {
         if !entry.file_type().is_file() || !is_image_path(path) {
             continue;
         }
-        let bytes = fs::read(path)?;
+        let bytes = match fs::read(path) {
+            Ok(b) => b,
+            Err(e) => {
+                eprintln!("warning: skipping {}: {e}", path.display());
+                continue;
+            }
+        };
         let sha256 = format!("{:x}", Sha256::digest(&bytes));
-        let img = image::open(path)?;
+        let img = match image::open(path) {
+            Ok(i) => i,
+            Err(e) => {
+                eprintln!("warning: skipping {}: {e}", path.display());
+                continue;
+            }
+        };
         let dhash = compute_dhash(&img);
         out.push(ImageEntry {
             path: path.to_path_buf(),