2.0.4: Merge AdminShellServiceProvider into CoreServiceProvider

Simplify to a single service provider so package registration stays
consistent: admin-shell wiring is now absorbed into CoreServiceProvider,
split by dependency. View/Blade-component/Livewire-namespace registration
stays unconditional (needed by /install's own Livewire component); the
persistent middleware, admin-shell routes, and authorization exception
rendering now register inside the gp247-installed.txt gate alongside the
rest of Core's DB-dependent bootstrap, fixing a pre-install 500 caused by
those routes depending on the admin middleware-group that only existed
inside that same gate (RISK-TECH-022).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>