Reported: the weekly schedule shows a schedule on a branch that was never
scheduled. Investigated against a restored tenant and the component is correct —
branch 2 gets only branch 2's sessions, and a branch with nothing gets an empty
grid. But chasing it found a real hole in the suite.

BranchScopedScreensTest searches rendered HTML for another branch's uuids. The
weekly schedule grid prints group names and times and no uuid at all, and
training_sessions was not even among the tables it collected uuids for. A
foreign session sitting in that grid would have left nothing in the markup to
search for, and the suite would have stayed green while the screen was wrong.
Several other grids and calendars are the same shape.

So this asserts one level earlier, on the objects rather than the markup. Every
component reachable at a parameterless URL is mounted under every branch, the
data handed to its views is captured through a view composer, and every model in
it that carries a branch_id must belong to the active branch — or be null only
where null still means "every branch" (people and the academy calendar), or
belong to a model that declares BRANCH_SCOPE_EXEMPT. It reads that declaration
rather than keeping a second list that would drift away from it.

Components come from the router rather than a hand-written list, so a screen
added next month is covered without anyone remembering.

1,188 component mounts across nine branches, 9.5M records inspected, no screen
handing its view another branch's record.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>