docs: columnMapping for replaces create/update lookup reuse

assets/schemas/skill-actions.schema.json

@@ -57,6 +57,12 @@
         "readOnly": {
           "type": "boolean",
           "description": "宿主数据管理表单只读展示该字段（仍会随提交传入 entrypoint）；用于行内/勾选预填的主键等"
+        },
+        "column": {
+          "type": "string",
+          "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"
         }
       }
     },
@@ -125,9 +131,18 @@
           "type": "object",
           "additionalProperties": { "type": "string", "minLength": 1 },
           "description": "可选。将 $row.$pk / $row.col / $selection.ids 等映射到 inputSchema 字段名，供 row/batch 预填。"
+        },
+        "columnMapping": {
+          "type": "object",
+          "additionalProperties": {
+            "type": "string",
+            "minLength": 1,
+            "pattern": "^[a-z][a-z0-9_]*$"
+          },
+          "description": "可选。将 inputSchema 属性名映射到业务表物理列名，供 replaces create/update 抽屉复用列 displayName / lookup options。"
         }
       },
-      "description": "表级绑定；toolbar 必填。可选 inputMapping 供行内/批量预填。concurrency/locks 勿写入。"
+      "description": "表级绑定；toolbar 必填。可选 inputMapping / columnMapping。concurrency/locks 勿写入。"
     },
     "action": {
       "type": "object",