Send signed outgoing webhooks

Fed by the records themselves, delivered only to public HTTPS addresses
checked at every attempt, retried, and switched off after repeated failures.
A submitter's details travel only to webhooks that opted into them.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/Providers/AuthServiceProvider.php

@@ -20,6 +20,7 @@ use App\Models\Talk;
 use App\Models\Technology;
 use App\Models\Testimonial;
 use App\Models\User;
+use App\Models\Webhook;
 use App\Policies\ApplicationPolicy;
 use App\Policies\CallPolicy;
 use App\Policies\CategoryPolicy;
@@ -37,6 +38,7 @@ use App\Policies\TalkPolicy;
 use App\Policies\TechnologyPolicy;
 use App\Policies\TestimonialPolicy;
 use App\Policies\UserPolicy;
+use App\Policies\WebhookPolicy;
 use App\Support\Permissions;
 use Illuminate\Support\Facades\Gate;
 use Illuminate\Support\ServiceProvider;
@@ -63,6 +65,7 @@ class AuthServiceProvider extends ServiceProvider
         Gate::policy(Repository::class, RepositoryPolicy::class);
         Gate::policy(User::class, UserPolicy::class);
         Gate::policy(Role::class, RolePolicy::class);
+        Gate::policy(Webhook::class, WebhookPolicy::class);
 
         // The one place a permission is granted — spatie's own gate check is
         // switched off (config/permission.php) so nothing answers before this.