Mobile and Admin Video Maintenance Fixes
Fixed video category rollback, Bilibili metadata handling, and mobile layout for videos, resources, and login popovers.
# Mobile and Admin Video Maintenance Fixes
This update continues polishing the videos area and admin workflow so mobile browsing and video maintenance feel steadier.
## Changes
- Default video category seeds now only insert missing categories, so admin-edited category names are no longer overwritten.
- Bilibili metadata fetching removes the unnecessary Origin header and adds detail API, mobile-page, and newer page-data fallbacks; unchanged video URLs no longer refetch metadata on every save.
- Admin video recognition now explains when the player URL was generated but metadata needs manual title, author, or thumbnail entry, and duplicate videos are blocked with a clear message.
- The videos list, resources area, login popover, signed-in account message, and video player window now have stronger mobile wrapping, single-column, and overflow protection.
- Disabled video categories are marked in the admin checkbox list so new videos are less likely to reuse disabled tags.
