test(forms): model tests, multi-tenancy, migration rollback (Phase 9)

UserProfileTest: belongs-to user, fillable/non-fillable boundaries,
settings cast, lastSubmittedAt accessor (null + max from user-subject
submissions only, ignoring drafts and is_test rows).

FormSchemaTest: ULID PK, OrganisationScope filtering, polymorphic owner
resolution to Event, purpose enum cast, hasMany fields/submissions, and
logSchemaChange() actually creates an activity-log entry.

FormFieldTest: belongs-to schema, field_type stored as string (not DB
enum), binding/translations array casts, hasMany values, soft-delete
preserves historical values, logFieldChange() creates an entry.

FormSubmissionTest: belongs-to schema, polymorphic subject resolution,
status enum cast, schema_snapshot array cast, hasMany values.

FormValueTest: belongs-to submission/field, value array cast, hasMany
options pivot rebuilt by observer, unique-pair DB constraint enforced.

MultiTenancyTest: OrganisationScope correctly filters FormSchema /
FormTemplate / FormFieldLibrary by route-resolved organisation. Pins
the FormSchemaWebhook un-scoped behaviour explicitly so a future scope
addition is an intentional decision, not an accident.

MigrationRollbackTest (group 'slow'): full migrate:fresh → rollback 14
S1 steps → assert all 13 form-builder tables dropped + legacy tables
intentionally retained → re-migrate and assert table list matches
snapshot. Plus a separate test exercising the populate-user-profiles
migration's down().

Supporting tweaks:
- UserProfile::lastSubmittedAt accessor now returns Carbon|null instead
  of a raw timestamp string — testable, and matches Eloquent convention.
- UserProfileFactory cooperates with UserObserver via newModel override
  (updates the auto-created row instead of inserting a duplicate).
- AppServiceProvider morph map extended with all 12 form-builder model
  keys so logSchemaChange/logFieldChange resolve under enforceMorphMap.

Suite: 945 passed (was 911), 2671 assertions.

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

api/database/factories/UserProfileFactory.php

@@ -8,7 +8,14 @@ use App\Models\User;
 use App\Models\UserProfile;
 use Illuminate\Database\Eloquent\Factories\Factory;
 
-/** @extends Factory<UserProfile> */
+/**
+ * @extends Factory<UserProfile>
+ *
+ * Note: UserObserver auto-creates a user_profiles row whenever a User is
+ * created. To avoid unique-constraint collisions, this factory cooperates
+ * with the observer: it updates the existing profile row (if any) rather
+ * than blindly inserting a new one.
+ */
 final class UserProfileFactory extends Factory
 {
     /** @return array<string, mixed> */
@@ -30,4 +37,19 @@ final class UserProfileFactory extends Factory
     {
         return $this->state(fn () => ['is_ambassador' => true]);
     }
+
+    public function newModel(array $attributes = []): UserProfile
+    {
+        $userId = $attributes['user_id'] ?? null;
+        if ($userId !== null) {
+            $existing = UserProfile::where('user_id', $userId)->first();
+            if ($existing !== null) {
+                $existing->forceFill($attributes)->save();
+
+                return $existing;
+            }
+        }
+
+        return parent::newModel($attributes);
+    }
 }