Bases are pages (isBase=true) and the casl rules already granted the
exact same Manage/Read level on the Base subject as on Page for every
space role (admin, writer, reader). The `Base` subject was therefore
pure duplication: any caller that needed to check base access either
went through pageAccessService (which uses Page internally) or did a
direct Page-equivalent ability.cannot(..., Base) check that produced
the same outcome as Page would have.
Drop SpaceCaslSubject.Base entirely — server enum, server union,
server factory rules, client enum, client union — and switch the two
remaining direct callers to Page:
- base.controller.ts `create` and list checks now use Page (matching
page.controller.ts's create/list).
- base-table.tsx's `canSave` now reads Page edit ability.
Net effect: one source of truth for "can this user view/edit/manage
content in this space," whether the content is a regular page or a
base. Existing role assignments behave identically; no migration
needed because permissions are computed per-request from the role,
not stored.
Philipinho