Add Phase 1 Identity & Access module (roles, tokens, panel auth, policies)

Implements T1.1-T1.4: Spatie role/permission seeding, Sanctum token
issuance for customer channels and the FastAPI agent (with an
ability-exact-match middleware to tell them apart), Filament admin
panel access restricted to admin-tier roles with the navigation group
order, and skeleton BookingPolicy/RoutePolicy gated on the seeded
permissions ahead of their models landing in later phases.

app-modules/identity/routes/identity-routes.php

@@ -1 +1,8 @@
 <?php
+
+use Illuminate\Support\Facades\Route;
+use Modules\Identity\Http\Controllers\TokenController;
+
+Route::prefix('api/v1')->middleware('api')->group(function () {
+    Route::post('/auth/token', [TokenController::class, 'store'])->name('identity.auth.token');
+});