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/app/Models/UserProfile.php

@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Models;
+
+use App\Enums\FormBuilder\FormSubmissionStatus;
+use App\Models\FormBuilder\FormSubmission;
+use Illuminate\Database\Eloquent\Casts\Attribute;
+use Illuminate\Database\Eloquent\Concerns\HasUlids;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+final class UserProfile extends Model
+{
+    use HasFactory;
+    use HasUlids;
+
+    protected $fillable = [
+        'user_id',
+        'bio',
+        'photo_url',
+        'emergency_contact_name',
+        'emergency_contact_phone',
+        'settings',
+    ];
+
+    /**
+     * System-managed fields are deliberately NOT fillable: reliability_score,
+     * is_ambassador.
+     *
+     * @var array<string, string>
+     */
+    protected $casts = [
+        'reliability_score' => 'decimal:2',
+        'is_ambassador' => 'bool',
+        'settings' => 'array',
+    ];
+
+    public function user(): BelongsTo
+    {
+        return $this->belongsTo(User::class);
+    }
+
+    /**
+     * Computed: the most recent submitted_at across submissions whose subject
+     * is this user (non-test only). Null when user has no submissions.
+     */
+    protected function lastSubmittedAt(): Attribute
+    {
+        return Attribute::make(
+            get: fn () => FormSubmission::query()
+                ->where('subject_type', 'user')
+                ->where('subject_id', $this->user_id)
+                ->where('status', FormSubmissionStatus::SUBMITTED)
+                ->where('is_test', false)
+                ->max('submitted_at'),
+        );
+    }
+}