refactor(field-mapper): sort filename-safe types for deterministic output

airtable/seatable의 FILENAME_SAFE_TYPES 배열만 정의 순서가 정렬되지 않은
상태로 남아 있었다. settings-tab은 이 배열을 join(', ')으로 "Filtered to: …"
안내 문구에 그대로 노출하므로, 정렬되지 않은 순서가 그대로 사용자에게 보이는
비결정적 출력이 된다.

- 두 배열을 알파벳순으로 정렬 — 이미 모든 SUBFOLDER_SAFE_TYPES(3개 provider)와
  supabase의 FILENAME_SAFE_TYPES/READ_ONLY_TYPES가 따르던 컨벤션과 일치
- FieldTypeMapper 인터페이스 JSDoc에 getFilenameSafeTypes/getSubfolderSafeTypes의
  sorted+deduplicated 계약 명시 — 테스트로만 암묵 보장되던 불변식을 문서화
- 두 매퍼 단위 테스트의 기대 순서 동기화

src/services/airtable-field-mapper.ts

@@ -16,10 +16,10 @@ import type { FieldTypeMapper, StandardFieldType } from '../types';
 // value is server-computed) but still safe to use as a filename source
 // because the computed value is stable and typically text-like.
 const FILENAME_SAFE_TYPES = [
+  'formula',
+  'number',
   'singleLineText',
   'singleSelect',
-  'number',
-  'formula',
 ] as const;
 
 const READ_ONLY_TYPES = [

src/services/seatable-field-mapper.ts

@@ -18,11 +18,11 @@ import type { FieldTypeMapper, StandardFieldType } from '../types';
 // `formula` appear here AND in READ_ONLY_TYPES below: they're great
 // stable identifiers but the sync pipeline must not push to them.
 const FILENAME_SAFE_TYPES = [
-  'text',
-  'single-select',
-  'number',
   'auto-number',
   'formula',
+  'number',
+  'single-select',
+  'text',
 ] as const;
 
 const READ_ONLY_TYPES = [

src/types/field-types.types.ts

@@ -83,14 +83,16 @@ export interface FieldTypeMapper {
   isSubfolderSafe(providerType: string): boolean;
 
   /**
-   * Returns all known provider-specific types that pass `isFilenameSafe`.
-   * Enables UIs to enumerate the whitelist without guessing.
+   * Returns all known provider-specific types that pass `isFilenameSafe`,
+   * sorted and deduplicated. Enables UIs to enumerate the whitelist without
+   * guessing.
    */
   getFilenameSafeTypes(): readonly string[];
 
   /**
-   * Returns all known provider-specific types that pass `isSubfolderSafe`.
-   * Used by settings-tab to filter the subfolder field dropdown.
+   * Returns all known provider-specific types that pass `isSubfolderSafe`,
+   * sorted and deduplicated. Used by settings-tab to filter the subfolder
+   * field dropdown.
    */
   getSubfolderSafeTypes(): readonly string[];
 

tests/services/airtable-field-mapper.test.ts

@@ -294,10 +294,10 @@ describe('airtableFieldMapper', () => {
     it('should return exactly the 4 filename-safe types', () => {
       const types = airtableFieldMapper.getFilenameSafeTypes();
       expect(types).toEqual([
+        'formula',
+        'number',
         'singleLineText',
         'singleSelect',
-        'number',
-        'formula',
       ]);
     });
 

tests/services/seatable-field-mapper.test.ts

@@ -252,11 +252,11 @@ describe('seatableFieldMapper', () => {
     it('should return exactly the 5 filename-safe types', () => {
       const types = seatableFieldMapper.getFilenameSafeTypes();
       expect(types).toEqual([
-        'text',
-        'single-select',
-        'number',
         'auto-number',
         'formula',
+        'number',
+        'single-select',
+        'text',
       ]);
     });