fix(api): make table lock flags read-only on the public v2 surface

The new PATCH /api/v2/tables/[tableId] accepted a `locks` object, gated
on workspace admin plus the table-locks feature. That still lets an API
key clear the guard placed there to stop it: `write` is the floor for
the endpoint, and admin keys are ordinary API keys, so a lock is no
longer a boundary the key cannot cross.

Locks stay readable on the table resource and enforcement is unchanged
(a locked verb still returns 423). Changing one is now a first-party
admin action only.

The v2 body is declared here rather than reusing the first-party
updateTableBodySchema, which keeps its `locks` field so the UI can still
toggle them. It is .strict(), so a request carrying `locks` is rejected
with a 400 naming the field instead of silently succeeding without
applying it.

Author: TheodoreSpeaks