Custom Contenteditable Editor with Formatting and Video Support

Test Steps:

• Click in the editor and type text.
• Click the bold or italic icon to format selected text or toggle formatting for new text.
• Click the image icon to insert an image and paste a URL (e.g., https://via.placeholder.com/400x300.png).
• Click the media icon to insert a video and paste a URL (YouTube, Shorts, BitChute, or Rumble, e.g., https://www.youtube.com/shorts/-8qC9VH8wgw, https://www.youtube.com/watch?v=dQw4w9WgXcQ, https://www.bitchute.com/video/abc123/, https://rumble.com/v17j3tt).
• Play video: Click the video to start playback.
• Resize video/image: Drag the black square (bottom-right corner).
• Delete video/image: Click the red "X" (top-right corner).
• Type text between or after: Click between elements or after last element and type.
• For Rumble, if video fails to load, it shows "Video not embeddable" with a link.

Note: Supported platforms: YouTube (including Shorts), BitChute, Rumble. YouTube Shorts use 9:16 (360x640), others use 16:9 (640x360) or 4:3 (BitChute). In Brave, disable Shields (lion icon) for this site to reduce errors. Test in Chrome/Firefox for full compatibility. Some Rumble videos may have embed restrictions.