feat(instance): refactor modify endpoint to support config types

- Change modify endpoint from `/modify/{field}` to `/modify` with POST
- Add support for two modification types: configFile and systemConfig
- Implement config file parsing using ini package for configFile type
- Update database schema to include name in update query
- Add comprehensive input validation and error handling
- Update documentation to reflect new API changes

README.md

@@ -261,12 +261,12 @@ X-Timestamp: 1704067200000
 
 ### 5. Modify frpc Instance
 
-**Endpoint:** `/frpcAct/instanceMgr/modify/{field}`  
+**Endpoint:** `/frpcAct/instanceMgr/modify`  
 **Method:** POST  
 **Content-Type:** application/json  
 **Auth Required:** Yes (token)
 
-You can modify multiple fields at once:
+Modify instance configuration. Supports two modification types: `configFile` (modify frpc config file) and `systemConfig` (modify system-level settings).
 
 **Request Headers:**
 ```
@@ -274,27 +274,83 @@ X-Token: your_token
 X-Timestamp: 1704067200000
 ```
 
+#### Type 1: Modify Config File (configFile)
+
+Modify fields in the `[common]` section of the frpc configuration file. Only `[common]` section fields can be modified, `[[proxies]]` sections will not be affected.
+
 **Request Body:**
 ```json
 {
   "instanceName": "my_frpc",
-  "name": "new_name",
-  "serverAddr": "192.168.1.1",
-  "serverPort": "7000",
-  "auth_method": "token",
-  "runUser": "www-data",
-  "bootAtStart": false
+  "instanceID": "1",
+  "type": "configFile",
+  "modifiedData": {
+    "server_addr": "192.168.1.1",
+    "server_port": "7000",
+    "auth_method": "token",
+    "auth_token": "my_secret_token"
+  }
 }
 ```
 
+| Field | Type | Required | Description |
+|-------|------|----------|-------------|
+| instanceName | string | Yes | Current instance name |
+| instanceID | string | Yes | Instance ID |
+| type | string | Yes | Modification type: `configFile` or `systemConfig` |
+| modifiedData | object | Yes | Key-value pairs of fields to modify in `[common]` section |
+
 **Response:**
 ```json
 {
   "success": true,
-  "message": "instance modified successfully",
+  "message": "Config file modified successfully",
   "data": {
-    "name": "new_name",
-    "configPath": "./configs/superfrpc_user_new_name.toml"
+    "instanceName": "my_frpc",
+    "instanceID": 1,
+    "configPath": "./configs/superfrpc_user_my_frpc.toml"
+  }
+}
+```
+
+#### Type 2: Modify System Config (systemConfig)
+
+Modify system-level settings such as instance name, boot-at-start configuration, and run user. These changes will also update the operating system service configuration.
+
+**Request Body:**
+```json
+{
+  "instanceName": "my_frpc",
+  "instanceID": "1",
+  "type": "systemConfig",
+  "modifiedData": {
+    "name": "new_frpc_name",
+    "bootAtStart": true,
+    "runUser": "www-data"
+  }
+}
+```
+
+| Field | Type | Required | Description |
+|-------|------|----------|-------------|
+| instanceName | string | Yes | Current instance name |
+| instanceID | string | Yes | Instance ID |
+| type | string | Yes | Modification type: `configFile` or `systemConfig` |
+| modifiedData.name | string | No | New instance name (renames config file if changed) |
+| modifiedData.bootAtStart | bool | No | Auto-start on system boot |
+| modifiedData.runUser | string | No | User to run the frpc instance as |
+
+**Response:**
+```json
+{
+  "success": true,
+  "message": "System config modified successfully",
+  "data": {
+    "instanceName": "new_frpc_name",
+    "instanceID": 1,
+    "configPath": "./configs/superfrpc_user_new_frpc_name.toml",
+    "bootAtStart": true,
+    "runUser": "www-data"
   }
 }
 ```