refactor(테이블타입): backend INSERT/UPDATE 8개 validate 백스톱

- TableManagementService.normalizeInputType(value, context) 오버로드 — user-insert/user-update-type 만 8개 검증, user-update-other/system-normalize 는 skip
- TableManagementService.updateColumnSettings: payload 의 input_type 키 존재 여부로 context 분기 (input_type 자체 변경 vs 다른 속성 변경)
- DdlService.addColumn / saveColumnMetadata: convertToInputType 결과를 USER_SELECTABLE_INPUT_TYPES (8개) 와 대조, 외이면 IllegalArgumentException

mapper XML 5곳 (categoryTree / entityJoin / tableCategoryValue / screenManagement / tableManagement / entityReference) 무변경 — READ 경로 12개 그대로.

spec: .omc/specs/deep-dive-table-type-storage-ui-separation.md (v3.2 §6.3)

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

backend-spring/src/main/java/com/erp/service/DdlService.java

@@ -39,6 +39,12 @@ public class DdlService extends BaseService {
         "id", "created_date", "updated_date", "company_code"
     );
 
+    /** 사용자가 신규 추가하는 컬럼에 허용되는 INPUT_TYPE 8종 (백엔드 백스톱) */
+    private static final Set<String> USER_SELECTABLE_INPUT_TYPES = Set.of(
+        "text", "number", "date", "code", "entity",
+        "numbering", "file", "image"
+    );
+
     public DdlService(JdbcTemplate jdbcTemplate, PlatformTransactionManager transactionManager) {
         this.jdbcTemplate = jdbcTemplate;
         this.transactionTemplate = new TransactionTemplate(transactionManager);
@@ -140,6 +146,12 @@ public class DdlService extends BaseService {
             transactionTemplate.execute(status -> {
                 jdbcTemplate.execute(ddlQuery);
                 String inputType = convertToInputType(column);
+                if (!USER_SELECTABLE_INPUT_TYPES.contains(inputType)) {
+                    throw new IllegalArgumentException(
+                        "INPUT_TYPE 은 다음 8개 중 하나여야 합니다: " + USER_SELECTABLE_INPUT_TYPES
+                        + " (받은 값: " + inputType + ")"
+                    );
+                }
                 String detailSettings = column.containsKey("detail_settings")
                     ? column.get("detail_settings").toString() : "{}";
                 Integer maxOrder = jdbcTemplate.queryForObject(
@@ -408,10 +420,17 @@ public class DdlService extends BaseService {
         // 사용자 정의 컬럼
         for (int i = 0; i < columns.size(); i++) {
             Map<String, Object> col = columns.get(i);
+            String inputType = convertToInputType(col);
+            if (!USER_SELECTABLE_INPUT_TYPES.contains(inputType)) {
+                throw new IllegalArgumentException(
+                    "INPUT_TYPE 은 다음 8개 중 하나여야 합니다: " + USER_SELECTABLE_INPUT_TYPES
+                    + " (받은 값: " + inputType + ")"
+                );
+            }
             String detailSettings = col.containsKey("detail_settings")
                 ? col.get("detail_settings").toString() : "{}";
             saveColumnMeta(tableName, (String) col.get("name"), companyCode,
-                convertToInputType(col), detailSettings, i);
+                inputType, detailSettings, i);
         }
     }