/claim #1985

Summary by cubic

Adds BigBlueButton as a new video conferencing provider with a dynamic location link and a VideoApiAdapter to create meetings. Implements Linear #1985 by registering the app in the store and wiring up meeting creation.

• New Features
  • New app: bigbluebuttonvideo (metadata, icon, package).
  • VideoApiAdapter to create meetings via the BigBlueButton API.
  • App keys schema for bbbHost and bbbSecret; falls back to test host if not set.
  • App store registration and exports for use under the “conferencing” variant.

^{Written for commit 57d10c4a4487dba49c123e38d233200be74a946b. Summary will update on new commits.}