feat: 编辑框合并说明/用途字段，编辑模式下允许修改说明

public/js/app.js

@@ -377,8 +377,7 @@ function openConfigModal(config, readonly) {
       : "配置值";
   document.getElementById("config-type").value = config ? config.type : "string";
   document.getElementById("config-value-range").value = config ? config.valueRange || "" : "";
-  document.getElementById("config-description").value = config ? config.description : "";
-  document.getElementById("config-purpose").value = config ? config.purpose || "" : "";
+document.getElementById("config-description").value = config ? config.description : "";
   document.getElementById("config-required").checked = config ? config.required === true : false;
   document.getElementById("config-exists").checked = config ? config.exists !== false : true;
   document.getElementById("config-range-preset").value = "";
@@ -400,8 +399,8 @@ function updateRangePresetVisibility() {
 
 /**
  * 根据模式和是否只读查看，设置配置模态框各字段的可编辑性
- * 规划模式：结构字段(类型/说明/用途/范围/键名/维度)可改，值不可改
- * 编辑模式：值可改，已有项的结构字段锁定
+* 规划模式：结构字段(类型/说明/范围/键名/维度)可改，值不可改
+ * 编辑模式：值、说明可改，已有项的其他结构字段锁定
  * 只读查看：全部禁用
  * @param {boolean} readonly - 是否只读查看
  * @returns {void}
@@ -409,8 +408,8 @@ function updateRangePresetVisibility() {
 function applyFieldPermissions(readonly) {
   const structFields = [
     "config-key", "config-type", "config-value-range", "config-required",
-    "config-default-value",
-    "config-description", "config-purpose",
+"config-default-value",
+    "config-description",
     "config-idc", "config-environment", "config-group",
   ];
   const valueField = "config-value";
@@ -444,10 +443,8 @@ function applyFieldPermissions(readonly) {
     const isNew = !state.editingConfigId;
     document.getElementById("config-type").disabled = !isNew;
     document.getElementById("config-value-range").disabled = !isNew;
-    document.getElementById("config-required").disabled = !isNew;
-    document.getElementById("config-default-value").disabled = !isNew;
-    document.getElementById("config-description").disabled = !isNew;
-    document.getElementById("config-purpose").disabled = !isNew;
+document.getElementById("config-required").disabled = !isNew;
+    document.getElementById("config-default-value").disabled = !isNew;
     document.getElementById("config-key").disabled = false;
     document.getElementById("config-idc").disabled = false;
     document.getElementById("config-environment").disabled = false;
@@ -474,9 +471,8 @@ function collectConfigForm() {
     defaultValue: document.getElementById("config-default-value").value,
     required: document.getElementById("config-required").checked,
     exists: document.getElementById("config-exists").checked,
-    description: document.getElementById("config-description").value.trim(),
-    purpose: document.getElementById("config-purpose").value.trim(),
-  };
+description: document.getElementById("config-description").value.trim(),
+  };
 }
 
 /**