feat(form-field): backfill form_fields.options to form_field_options

Atomic data migration. Every options datum in the database — in
form_fields and form_field_library, their translations bags, and the
form_submissions.schema_snapshot + form_templates.schema_snapshot JSON
blobs — is converted to the new relational rich-shape representation.

Strict dispatch per §17.4.4 / §8.7 convention:
  - Fail on field_type ∉ {RADIO, SELECT, MULTISELECT, CHECKBOX_LIST}
    carrying non-null options (post-WS-5b TAG_PICKER seed-bug indicator)
  - Fail on non-flat-string-array options shape
  - Fail on translations.{locale}.options[] length mismatch
  - Fail on non-string / >255-char translated labels
  - Fail on any residual translations.{locale}.options key after
    step C migration

Snapshot rewrite in-place: both form_submissions.schema_snapshot and
form_templates.schema_snapshot walk fields[*] and rewrite options to
the new rich-shape, strip per-locale options[] from the parallel
translations bag. Zero-compromise directive — no reader tolerance for
pre-WS-5d shape in commit 3 onwards.

Rollback reconstructs JSON column shapes plus translations bags.
Forward+back pair safe as a unit; partial rollback unsupported.

FormFieldService::insertFromLibrary switches from JSON-copy to
FormFieldOptionService::copyOptions row-clone per addendum Q3 row-copy
mandate. The field's own translations bag no longer carries
{locale}.options keys — those live on option rows now.

Seeders and factories switch to service-level option creation:
  - FormBuilderDevSeeder.canonicalFields keeps flat-string options as
    its data shape; FormField::create no longer receives an options
    key, the post-create FormFieldOptionService::replaceOptions call
    inserts the rich rows. The same applies to
    seedEventRegistrationShowcaseSchema. The vergoedingstype field's
    legacy {label, description} object shape (a pre-WS-5d seed-bug
    that the strict backfill would reject) is normalised to flat
    strings; the descriptions are dropped.
  - seedSystemTemplates embeds rich-shape options in the template
    snapshot — no flat-array snapshot data remains in newly-seeded
    rows.
  - FormFieldFactory + FormFieldLibraryFactory drop the options
    default; new ::withOptions() helper accepts either flat strings
    (each becomes value+label) or full spec arrays and routes through
    the service.

JSON columns (form_fields.options, form_field_library.options) remain
present and writable via fillable; column-drop lands in commit 5.
Reads from the JSON column still exist in resources, snapshot writer,
FormRequests, FormValueService, and FilterRegistryController — commit
3 switches those all atomically.

Migration step-count tests in WS-5a/b/c bumped by 1 to account for
the new backfill_form_field_options migration on the migration stack.

Tests: 1182 → 1193 green (+11 tests / +56 assertions).

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

api/tests/Feature/FormBuilder/ConditionalLogic/ConditionalLogicBackfillTest.php

@@ -31,10 +31,11 @@ final class ConditionalLogicBackfillTest extends TestCase
 
     public function test_forward_backfill_builds_nested_tree_from_legacy_json(): void
     {
-        // Roll back the WS-5d create-options + WS-5c drop-cl-col + WS-5c
-        // backfill-cl migrations to land in the conditional-logic JSON-era
-        // state with no relational form_field_options table yet.
-        $this->artisan('migrate:rollback', ['--step' => 3])->assertSuccessful();
+        // Roll back the WS-5d backfill-options + create-options + WS-5c
+        // drop-cl-col + WS-5c backfill-cl migrations to land in the
+        // conditional-logic JSON-era state with no relational
+        // form_field_options table yet.
+        $this->artisan('migrate:rollback', ['--step' => 4])->assertSuccessful();
         $this->assertTrue(Schema::hasColumn('form_fields', 'conditional_logic'));
 
         $fieldId = $this->seedFieldWithJson([
@@ -155,7 +156,7 @@ final class ConditionalLogicBackfillTest extends TestCase
         ]);
 
         // Roll back only the backfill migration — writes the JSON back.
-        $this->artisan('migrate:rollback', ['--step' => 3])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 4])->assertSuccessful();
 
         $reconstructed = DB::table('form_fields')
             ->where('id', $fieldId)
@@ -182,7 +183,7 @@ final class ConditionalLogicBackfillTest extends TestCase
 
     public function test_unknown_top_level_key_fails_migration(): void
     {
-        $this->artisan('migrate:rollback', ['--step' => 3])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 4])->assertSuccessful();
 
         $this->seedFieldWithJson([
             'hide_when' => ['all' => [['field_slug' => 'x', 'operator' => 'equals', 'value' => 1]]],
@@ -195,7 +196,7 @@ final class ConditionalLogicBackfillTest extends TestCase
 
     public function test_unknown_comparison_operator_fails_migration(): void
     {
-        $this->artisan('migrate:rollback', ['--step' => 3])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 4])->assertSuccessful();
 
         $this->seedFieldWithJson([
             'show_when' => ['all' => [['field_slug' => 'x', 'operator' => 'matches_regex', 'value' => 'y']]],