fix subdirectory search and tag highlighting edge cases

- filter notes by relative path instead of bare filename so searching
  "/subdir" or "subdir" matches notes inside that subdirectory
- strip leading "/" from search text before matching so both forms work
- tighten tag regex in _extractTags and _formatTags: require a letter
  after the symbol and a non-word boundary before it ((?<!\S)) to avoid
  matching phone numbers (+44…) and email-local-part suffixes
- fix subdir/notename creation: use contains('/') instead of
  startsWith('/') so names without a leading slash are split correctly

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/note_list.dart

@@ -294,7 +294,7 @@ Happy note taking! ✨
 
   /// Extracts unique tags sorted by +, @, #
   Set<String> _extractTags(String content) {
-    final tagPattern = RegExp(r'([#@+][a-zA-Z][a-zA-Z0-9_]*)');
+    final tagPattern = RegExp(r'(?<!\S)[#@+][a-zA-Z][a-zA-Z0-9_]*');
     final matches = tagPattern.allMatches(content).map((m) => m.group(0)!).toSet();
 
     // Sort the tags in order: +tags first, @contexts second, #hashtags last
@@ -325,8 +325,11 @@ Happy note taking! ✨
       final searchTags = terms.where((t) => t.startsWith(RegExp(r'[#@+]'))).toSet();
       final searchText = terms.where((t) => !t.startsWith(RegExp(r'[#@+]'))).join(' ');
 
+      // Strip leading '/' so "/subdir" and "subdir" match the same notes
+      final normalizedSearch = searchText.replaceFirst(RegExp(r'^/'), '');
+
       filteredNotes = notes.where((note) {
-        final filename = note.uri.pathSegments.last.toLowerCase();
+        final relativePath = path.relative(note.path, from: notesDirectoryPath!).toLowerCase();
         final noteTags = _extractTags(note.readAsStringSync());
 
         // ✅ Read file content ONLY if `Include File Content` is enabled
@@ -337,9 +340,9 @@ Happy note taking! ✨
             noteTags.any((noteTag) => noteTag.startsWith(tag)));
 
         if (!_includeFileContent) {
-          return filename.contains(searchText) && matchesTags;
+          return relativePath.contains(normalizedSearch) && matchesTags;
         } else {
-          return (filename.contains(searchText) || content.contains(searchText)) && matchesTags;
+          return (relativePath.contains(normalizedSearch) || content.contains(normalizedSearch)) && matchesTags;
         }
       }).toList();
     });
@@ -360,7 +363,7 @@ Happy note taking! ✨
   }
 
   List<InlineSpan> _formatTags(String content) {
-    final tagPattern = RegExp(r'([#@+][a-zA-Z0-9_]+)');
+    final tagPattern = RegExp(r'(?<!\S)[#@+][a-zA-Z][a-zA-Z0-9_]*');
     final Set<String> tagSet = {}; // Avoid duplicate tags
 
     for (final match in tagPattern.allMatches(content)) {
@@ -405,7 +408,7 @@ Happy note taking! ✨
         }
       }
 
-      if (notePath.startsWith('/')) {
+      if (notePath.contains('/')) {
         final parts = notePath.split('/');
         parts.removeWhere((element) => element.isEmpty);
         if (parts.length > 1) {