refactor(form-field): extract legacy conditional_logic shape normaliser

Three byte-identical copies of `normaliseLegacyGroupShape` lived in
FormFieldService, StoreFormFieldRequest, and UpdateFormFieldRequest.
WS-5d (form_fields.options) would have been the fourth copy. Hoist
the helper to a single public static on FormFieldConditionalLogicService
and have all three call sites delegate.

Implementation:

  - `FormFieldConditionalLogicService::normaliseLegacyShape(array)` —
    pure recursive passthrough. Translates the ARCH §8 JSON group shape
    (`{"all": [...]}` / `{"any": [...]}`) into the service's internal
    `{"operator", "children"}` form. Does NOT validate; malformed shapes
    return as-is and surface downstream as
    `InvalidConditionalLogicSpecException` from `assertSpecsValid`.
  - Group operator catalogue sourced from
    `FormFieldConditionalLogicGroupOperator::values()` instead of an
    `['all', 'any']` literal — single source of truth for future
    operator additions.
  - All three call sites switched to the static method. The two
    FormRequests reach it via the existing `use` import; FormFieldService
    sits in the same namespace.

Behaviour preserved exactly:

  - Existing FormFieldApiTest (cyclic logic rejection),
    FormFieldStrictConditionalLogicRequestTest (strict-validator
    rejection paths), and FormFieldConditionalLogicServiceTest
    (service-level paths) all green without modification.

New unit tests pin the passthrough contract (8 tests):

  - Valid ALL / ANY translations
  - Recursive nested-group translation (depth 2)
  - Internal shape unchanged
  - Condition leaf passthrough
  - Unknown group key (`xor`) returned unchanged for downstream
    `assertSpecsValid` to reject
  - Empty array unchanged
  - Non-array children stripped silently

Tests: 1150 → 1158 green (3110 → 3124 assertions).

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

api/app/Enums/FormBuilder/FormFieldConditionalLogicGroupOperator.php

@@ -14,4 +14,16 @@ enum FormFieldConditionalLogicGroupOperator: string
 {
     case All = 'all';
     case Any = 'any';
+
+    /**
+     * String values of every case — used by the legacy-shape normaliser
+     * to walk `{"all": [...]}` / `{"any": [...]}` JSON nodes without
+     * duplicating the operator catalogue at the call site.
+     *
+     * @return list<string>
+     */
+    public static function values(): array
+    {
+        return array_map(static fn (self $case): string => $case->value, self::cases());
+    }
 }