Add comprehensive feature tests for WorkspaceController covering all
CRUD operations and workspace switching logic. 46 tests with 97
assertions verify: listing with pagination/filtering/search, show with
access control, create with owner attachment, update with role-based
permissions (owner/admin/member/outsider), delete with ownership and
single-workspace guards, switch with hub-domain scoping and transaction
atomicity, and current workspace resolution with fallback.
Fixes#29
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
