Replace react-markdown with TipTap read-only editor for TextView component.
Changes:
- Create TipTap extensions folder with custom Hashtag and VideoEmbed nodes
- Hashtag extension: clickable hashtags with tag colors and filter integration
- VideoEmbed extension: YouTube and Rumble iframe embeds
- Add preprocessMarkdown utility for URL, email, video link, and hashtag conversion
- Migrate TextView to use TipTap with StarterKit, Markdown, Link extensions
- Remove unused itemId prop from TextView and all callers
Known issue: Popup buttons may not work correctly when TextView has content
due to Leaflet's handling of contenteditable elements. To be fixed in follow-up.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
