Merge 7 single-action pipeline controllers (checkVersion, download,
unzip, copy, delete, migrate, finish) into UpdateController with named
methods. Remove dead UpdateController that duplicated the same logic
but wasn't referenced in routes. Extract shared owner check into
private ensureOwner() helper. Route URLs unchanged.
V1/Admin -> Company (company-scoped controllers)
V1/SuperAdmin -> Admin (platform-wide admin controllers)
V1/Customer -> CustomerPortal (customer-facing portal)
V1/Installation -> Setup (installation wizard)
V1/PDF -> Pdf (consistent casing)
V1/Modules -> Modules (drop V1 prefix)
V1/Webhook -> Webhook (drop V1 prefix)
The V1 prefix served no purpose - API versioning is in the route prefix
(/api/v1/), not the controller namespace. "Admin" was misleading for
company-scoped controllers. "SuperAdmin" is now simply "Admin" for
platform administration.
