* fix(boards): add permissions to board summary schema to fix manage page crash
The getAllBoards query fetches userPermissions and groupPermissions
from the DB, but boardSummarySchema (the output validator) did not
include them. tRPC stripped the fields, causing a TypeError when
getBoardPermissionsAsync called .some() on undefined.
* fix(backup): cast Buffer to Uint8Array for NextResponse body
Node 24 narrowed the BodyInit type, making Buffer incompatible.
Wrapping in Uint8Array satisfies the type constraint.
* fix(lint): remove forbidden non-null assertions across backup and board code
Replace non-null assertions with safe guards, optional chaining, and
for-of iteration so oxlint passes in CI. Also remove unused Collapse import.
Thomas
