fix: Chapter numbering and preserve custom titles on segment reorder (#1435)

* FIX: Preserve custom chapter titles when renumbering (151)

Updated the renumberAllSegments function to only update chapter titles that match the default 'Chapter X' pattern, preserving any custom titles. Also ensured segments are renumbered after updates for consistent chronological naming.

* build assets (chapters editor)

frontend-tools/chapters-editor/client/src/hooks/useVideoChapters.tsx

@@ -20,7 +20,7 @@ const useVideoChapters = () => {
         // Sort by start time to find chronological position
         const sortedSegments = allSegments.sort((a, b) => a.startTime - b.startTime);
         // Find the index of our new segment
-        const chapterIndex = sortedSegments.findIndex(seg => seg.startTime === newSegmentStartTime);
+        const chapterIndex = sortedSegments.findIndex((seg) => seg.startTime === newSegmentStartTime);
         return `Chapter ${chapterIndex + 1}`;
     };
 
@@ -30,10 +30,16 @@ const useVideoChapters = () => {
         const sortedSegments = [...segments].sort((a, b) => a.startTime - b.startTime);
 
         // Renumber each segment based on its chronological position
-        return sortedSegments.map((segment, index) => ({
-            ...segment,
-            chapterTitle: `Chapter ${index + 1}`
-        }));
+        // Only update titles that follow the default "Chapter X" pattern to preserve custom titles
+        return sortedSegments.map((segment, index) => {
+            const currentTitle = segment.chapterTitle || '';
+            const isDefaultTitle = /^Chapter \d+$/.test(currentTitle);
+
+            return {
+                ...segment,
+                chapterTitle: isDefaultTitle ? `Chapter ${index + 1}` : currentTitle,
+            };
+        });
     };
 
     // Helper function to parse time string (HH:MM:SS.mmm) to seconds
@@ -124,9 +130,7 @@ const useVideoChapters = () => {
                 let initialSegments: Segment[] = [];
 
                 // Check if we have existing chapters from the backend
-                const existingChapters =
-                    (typeof window !== 'undefined' && (window as any).MEDIA_DATA?.chapters) ||
-                    [];
+                const existingChapters = (typeof window !== 'undefined' && (window as any).MEDIA_DATA?.chapters) || [];
 
                 if (existingChapters.length > 0) {
                     // Create segments from existing chapters
@@ -564,8 +568,11 @@ const useVideoChapters = () => {
                     `Updating segments with action: ${actionType}, recordHistory: ${isSignificantChange ? 'true' : 'false'}`
                 );
 
+                // Renumber all segments to ensure proper chronological naming
+                const renumberedSegments = renumberAllSegments(e.detail.segments);
+
                 // Update segment state immediately for UI feedback
-                setClipSegments(e.detail.segments);
+                setClipSegments(renumberedSegments);
 
                 // Always save state to history for non-intermediate actions
                 if (isSignificantChange) {
@@ -573,7 +580,7 @@ const useVideoChapters = () => {
                     // ensure we capture the state properly
                     setTimeout(() => {
                         // Deep clone to ensure state is captured correctly
-                        const segmentsClone = JSON.parse(JSON.stringify(e.detail.segments));
+                        const segmentsClone = JSON.parse(JSON.stringify(renumberedSegments));
 
                         // Create a complete state snapshot
                         const stateWithAction: EditorState = {