Add a YouTube uploader that follows the existing cookie-based browser
automation pattern (uploader/youtube_uploader + sau youtube CLI:
login/check/upload-video). Supports title/description/tags, thumbnail,
adding to a playlist (for series), and visibility (public/unlisted/private).
Browser automation is used instead of the official Data API on purpose:
videos uploaded by an unaudited API project are force-locked to private
and cannot be made public without Google's compliance audit, which is
impractical for personal/single-channel use. Browser automation has no
such restriction and matches how every other platform here works.
- Add tag count validation (max 10) in both CLI and uploader layers
- CLI: exit with error if tags > 10, prompt user to reduce
- Uploader: truncate to first 10 with warning as fallback
- Prevents infinite loop when XHS UI rejects excess tags
- Add check_original_declaration() to auto-check original content
declaration before publishing (video and note modes)
- Gracefully skips if the option is not present on the page