- 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

Fix: Use conditional links for bottom navigation.
Fix: Margin error on queued messages.

Fix: Copy ID copies wrong ID.
Messaging: Add context menu to avatar / username.

Focus editor / box properly.

Add bars + header + sidebar to channels.