Phase 6: security & ops hardening (T6.1-T6.5)

- T6.1: named rate limiters (api-read/api-write/api-auth/api-webhooks),
  applied per module route group with tighter limits on booking/payment
  writes and the KBZ webhook than read-only catalog/routing endpoints.
- T6.2: install spatie/laravel-activitylog; LogsActivity on Booking/
  Payment/Refund status transitions and catalog/pricing admin CRUD
  (EvCompany, Destination, DepartureTimeSlot, EvRoute, RoutePricing).
  New IdentityPlugin with a read-only AuditLogResource gated by
  view_audit_log.
- T6.3: JSON error envelope for api/* in bootstrap/app.php (401/403/404/
  405/429/500 fallback), plus PaymentGatewayException (422 declined /
  502 unavailable).
- T6.4: feature tests proving the FastAPI agent token gets 403 on
  refund/cancel-not-owned and 405 (no write handler) on catalog/routing
  writes.
- T6.5: install gboquizosanchez/filament-log-viewer with a custom
  Filament admin theme (required for its views' Tailwind classes to
  compile), LOG_CHANNEL/FILAMENT_LOG_VIEWER_DRIVER=daily, registered
  under Operations in the sidebar.

252 tests passing.

database/migrations/2026_08_09_093457_create_activity_log_table.php

@@ -0,0 +1,23 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::create('activity_log', function (Blueprint $table) {
+            $table->id();
+            $table->string('log_name')->nullable()->index();
+            $table->text('description');
+            $table->nullableMorphs('subject', 'subject');
+            $table->string('event')->nullable();
+            $table->nullableMorphs('causer', 'causer');
+            $table->json('attribute_changes')->nullable();
+            $table->json('properties')->nullable();
+            $table->timestamps();
+        });
+    }
+};