fix: Show default chapter names in textarea instead of placeholder text (#1428)

* Refactor chapter filtering and auto-save logic

Simplified chapter filtering to only exclude empty titles, allowing default chapter names. Updated auto-save logic to skip saving when there are no chapters or mediaId. Removed unused helper function and improved debug logging.

* Show default chapter title in editor and set initial title

The chapter title is now always displayed in the textarea, including default names like 'Chapter 1'. Also, the initial segment is created with 'Chapter 1' as its title instead of an empty string for better clarity.

* build assets

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

@@ -150,7 +150,7 @@ const useVideoChapters = () => {
                     // Create a default segment that spans the entire video on first load
                     const initialSegment: Segment = {
                         id: 1,
-                        chapterTitle: '',
+                        chapterTitle: 'Chapter 1',
                         startTime: 0,
                         endTime: video.duration,
                     };