feat(server): normalize etags from webdav to properly check for file changes

src/webdav_xml_parser.rs

@@ -83,7 +83,13 @@ pub fn parse_propfind_response(xml_text: &str) -> Result<Vec<FileInfo>> {
                                 resp.content_type = Some(text.trim().to_string());
                             }
                             "getetag" => {
-                                resp.etag = Some(text.trim().to_string());
+                                // Normalize ETag by removing quotes and weak ETag prefix
+                                let etag = text.trim();
+                                let normalized = etag
+                                    .trim_start_matches("W/")
+                                    .trim_matches('"')
+                                    .to_string();
+                                resp.etag = Some(normalized);
                             }
                             "status" if in_propstat => {
                                 // Check if status is 200 OK

tests/webdav_sync_tests.rs

@@ -182,6 +182,26 @@ fn test_etag_change_detection() {
     assert_eq!(normalized_etag, old_etag);
 }
 
+#[test]
+fn test_etag_normalization() {
+    // Test various ETag formats that WebDAV servers might return
+    let test_cases = vec![
+        ("abc123", "abc123"),                    // Plain ETag
+        ("\"abc123\"", "abc123"),                // Quoted ETag
+        ("W/\"abc123\"", "abc123"),              // Weak ETag
+        ("\"abc-123-def\"", "abc-123-def"),      // Quoted with dashes
+        ("W/\"abc-123-def\"", "abc-123-def"),    // Weak ETag with dashes
+    ];
+    
+    for (input, expected) in test_cases {
+        let normalized = input
+            .trim_start_matches("W/")
+            .trim_matches('"');
+        assert_eq!(normalized, expected, 
+            "Failed to normalize ETag: {} -> expected {}", input, expected);
+    }
+}
+
 #[test]
 fn test_path_normalization() {
     let test_paths = vec![