Hosting dev-access: resolve via central identity API (shadow mode)

Consolidate the inline HostingAccountMember lookups (Overview/Search/Hosting
Product/Afia controllers) into HostingAccessResolver, which can source hosting
developer-access from the monolith's central /identity/hosting/developer-access
(correlating cPanel usernames to local account ids). Shadow mode by default
(HOSTING_CENTRAL_DEV_ACCESS=false): local hosting_account_members stays
authoritative and divergence from central is logged; flip the flag to cut over.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/Http/Controllers/Hosting/OverviewController.php

@@ -6,10 +6,10 @@ use App\Http\Controllers\Controller;
 use App\Models\CustomerHostingOrder;
 use App\Models\HostedSite;
 use App\Models\HostingAccount;
-use App\Models\HostingAccountMember;
 use App\Models\HostingOrder;
 use App\Models\HostingProduct;
 use App\Models\User;
+use App\Services\Hosting\HostingAccessResolver;
 use Illuminate\Database\Eloquent\Collection;
 use Illuminate\Support\Collection as SupportCollection;
 use Illuminate\Http\Request;
@@ -100,9 +100,7 @@ class OverviewController extends Controller
     {
         $sharedTypes = $this->sharedTypes();
 
-        $sharedAccountIds = HostingAccountMember::query()
-            ->where('user_id', $user->id)
-            ->pluck('hosting_account_id');
+        $sharedAccountIds = app(HostingAccessResolver::class)->sharedAccountIds($user);
 
         $hostingAccounts = HostingAccount::query()
             ->where(function ($query) use ($user, $sharedAccountIds) {