docs: form field type contract Action/CRUD symmetry (v1.0.77)

assets/schemas/skill-actions.schema.json

@@ -117,6 +117,16 @@
           "minLength": 1,
           "pattern": "^[a-z][a-z0-9_]*$",
           "description": "可选。绑定业务表物理列名；replaces create/update 时宿主可复用该列的中文名与 lookup 下拉"
+        },
+        "display_type": {
+          "type": "string",
+          "enum": ["textarea", "date", "datetime_unix_seconds", "url", "email"],
+          "description": "可选。表单控件提示；与 format 二选一即可。须与 CRUD display_type 语义对齐（见 ACTIONS.md / SCHEMA.md）。"
+        },
+        "format": {
+          "type": "string",
+          "enum": ["textarea", "date", "datetime_unix_seconds", "url", "email"],
+          "description": "可选。display_type 别名，语义相同。"
         }
       }
     },