feat(forms): add Eloquent models, observer, events, activity-log helpers

Phase 4 of S1.

Models (app/Models/FormBuilder/): FormSchema, FormSchemaSection, FormField,
FormSubmission, FormValue, FormValueOption, FormTemplate, FormFieldLibrary,
FormSchemaWebhook, FormWebhookDelivery, FormSubmissionSectionStatus,
FormSubmissionDelegation. Plus UserProfile at app/Models/ (user-universal).

OrganisationScope applied on: FormSchema, FormTemplate, FormFieldLibrary.
FormSchemaWebhook documents inherited-scope discipline (OrganisationScope's
strategies — organisation_id/event_id/festival_section_id — don't cover
form_schema_id; direct queries would leak across orgs, so must go via
$schema->webhooks()).

User::profile()/getOrCreateProfile(), Event::formSchemas() (morphMany),
Person::formSubmissions() (morphMany).

Morph map enforced in AppServiceProvider with 28 keys covering every model
that appears as activitylog subject/causer. Also updated
OrganisationDashboardService (and its test) to query activitylog via
getMorphClass() instead of FQCN.

Activity log strategy: nuanced explicit calls (logSchemaChange on FormSchema,
logFieldChange on FormField) — no LogsActivity trait. Suppression for bulk
fixtures via App\Support\ActivityLog::suppressed(fn() => ...) which flips
config('activitylog.enabled') around a callback. Both our explicit calls
and spatie's trait on Organisation respect the flag via ActivityLogger::log().

FormValueObserver (app/Observers/FormBuilder/) populates value_indexed/
value_number/value_date/value_bool on save per field.value_storage_hint,
rebuilds form_value_options pivot on multi-value filterable fields, cleans
up on delete. Memoised field cache avoids N+1. Registered in AppServiceProvider.

9 lightweight event classes (app/Events/FormBuilder/) as SerializesModels
containers — submission lifecycle signatures lock in for S2 services, no
listeners yet.

Factories for all models with Dutch fake data (fake('nl_NL')). FormSchema
factory uses defaultSubmissionMode(); FormField factory uses
recommendedValueStorageHint().

Tests: 9 new observer tests (all pass); full suite 910/910 (up from 901).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

api/database/factories/FormBuilder/FormSubmissionFactory.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Database\Factories\FormBuilder;
+
+use App\Enums\FormBuilder\FormSubmissionStatus;
+use App\Models\FormBuilder\FormSchema;
+use App\Models\FormBuilder\FormSubmission;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+/** @extends Factory<FormSubmission> */
+final class FormSubmissionFactory extends Factory
+{
+    protected $model = FormSubmission::class;
+
+    /** @return array<string, mixed> */
+    public function definition(): array
+    {
+        return [
+            'form_schema_id' => FormSchema::factory(),
+            'subject_type' => null,
+            'subject_id' => null,
+            'submitted_by_user_id' => null,
+            'status' => FormSubmissionStatus::DRAFT,
+            'is_test' => false,
+            'submitted_in_locale' => 'nl',
+        ];
+    }
+
+    public function submitted(): static
+    {
+        return $this->state(fn () => [
+            'status' => FormSubmissionStatus::SUBMITTED,
+            'submitted_at' => now(),
+        ]);
+    }
+
+    public function test(): static
+    {
+        return $this->state(fn () => ['is_test' => true]);
+    }
+}