Fix links in spoilers opening when revealing.
Fix unread icon appearing for home.
Fix unreads not being acknowledged.

Revert mobile change.
Messages: Add channel id matching.

Translate age gate.
Add additional limitations on KaTeX.
Prevent any message overflow.

Hook events into Markdown render using ref.

- replaced many uses of `as any` with another more specific cast `as T`
- filled in missing typed for items that needed to be typed
  - new runtime code was added where necessary to satisfy the new types with comments
- added missing theme variable "sidebar-active" to the Theme variables
- forms using `react-hook-form` are now typechecked
- changed some instances of `target` into `currentTarget` while removing `as any` assertions

Add profile links / app links back.
Add quoting / mentioning back.