refactor(api): simplify instance management endpoints

- Change delete endpoint to use request body instead of path parameter
- Modify endpoint now takes field as path parameter and instance name in body
- Update README to reflect API changes
- Remove unused description field from software info
- Fix error message in auth token lookup

frpc.go

@@ -224,7 +224,7 @@ func CreateInstanceHandler(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
-func DeleteInstanceHandler(w http.ResponseWriter, r *http.Request, instanceName string) {
+func DeleteInstanceHandler(w http.ResponseWriter, r *http.Request) {
 	if r.Method != http.MethodPost {
 		SendErrorResponse(w, http.StatusMethodNotAllowed, "Invalid request method")
 		return
@@ -238,6 +238,19 @@ func DeleteInstanceHandler(w http.ResponseWriter, r *http.Request, instanceName
 	}
 	defer r.Body.Close()
 
+	var reqMap map[string]interface{}
+	if err := json.Unmarshal(body, &reqMap); err != nil {
+		postLog.Error(fmt.Sprintf("[DeleteInstanceHandler] Failed to unmarshal request body: %v", err))
+		SendErrorResponse(w, http.StatusBadRequest, "Invalid request format")
+		return
+	}
+
+	instanceName := getStringFromMap(reqMap, "instanceName")
+	if instanceName == "" {
+		SendErrorResponse(w, http.StatusBadRequest, "instanceName is required")
+		return
+	}
+
 	userID, _, err := ValidateRequestWithBody(w, r, body)
 	if err != nil {
 		postLog.Error(fmt.Sprintf("[DeleteInstanceHandler] Failed to validate request body: %v", err))
@@ -304,7 +317,7 @@ func DeleteInstanceHandler(w http.ResponseWriter, r *http.Request, instanceName
 	})
 }
 
-func ModifyInstanceHandler(w http.ResponseWriter, r *http.Request, instanceName string) {
+func ModifyInstanceHandler(w http.ResponseWriter, r *http.Request, field string) {
 	if r.Method != http.MethodPost {
 		postLog.Error(fmt.Sprintf("[ModifyInstanceHandler] Invalid request method: %s", r.Method))
 		SendErrorResponse(w, http.StatusMethodNotAllowed, "Invalid request method")
@@ -326,6 +339,12 @@ func ModifyInstanceHandler(w http.ResponseWriter, r *http.Request, instanceName
 		return
 	}
 
+	instanceName := getStringFromMap(reqMap, "instanceName")
+	if instanceName == "" {
+		SendErrorResponse(w, http.StatusBadRequest, "instanceName is required")
+		return
+	}
+
 	userID, _, err := ValidateRequestWithBody(w, r, body)
 	if err != nil {
 		postLog.Error(fmt.Sprintf("[ModifyInstanceHandler] Failed to validate request body: %v", err))