refactor: harden client runtime and exports

scenes/ui/CourseBoardPanel.gd

@@ -8,8 +8,8 @@ extends Control
 # ============================================================================
 
 const MOVEMENT_ACTIONS: Array[String] = ["move_left", "move_right", "move_up", "move_down"]
-const NetworkConfig = preload("res://_Core/utils/NetworkConfig.gd")
 const API_PATH: String = "/course-resources/datawhale"
+const REQUEST_TIMEOUT: float = 18.0
 const PANEL_SIZE: Vector2 = Vector2(1500, 1020)
 const MIN_MARGIN: Vector2 = Vector2(24, 24)
 const CARD_SIZE: Vector2 = Vector2(320, 348)
@@ -24,7 +24,6 @@ var _overlay: ColorRect
 var _panel: Control
 var _grid: GridContainer
 var _statusLabel: Label
-var _request: HTTPRequest
 var _isOpen: bool = false
 var _transitionTween: Tween
 
@@ -124,10 +123,6 @@ func _buildUi() -> void:
 	root.add_child(_buildGridPanel())
 	root.add_child(_buildFooter())
 
-	_request = HTTPRequest.new()
-	_request.timeout = 18.0
-	_request.request_completed.connect(_onRequestCompleted)
-	add_child(_request)
 	_updatePanelAlpha(0.0, 0.0)
 
 func _buildHeader() -> Control:
@@ -222,23 +217,15 @@ func _buildFooter() -> Control:
 func _fetchCourses() -> void:
 	_statusLabel.text = "正在同步 Datawhale 课程..."
 	_clearChildren(_grid)
-	var err := _request.request("%s%s" % [NetworkConfig.get_api_base_url(), API_PATH])
-	if err != OK:
-		_statusLabel.text = "课程加载失败：%s" % error_string(err)
-
-func _onRequestCompleted(result: int, responseCode: int, _headers: PackedStringArray, body: PackedByteArray) -> void:
-	if result != HTTPRequest.RESULT_SUCCESS or responseCode < 200 or responseCode >= 300:
-		_statusLabel.text = "课程加载失败，请稍后再试"
+	var api_client := get_node_or_null("/root/ApiClient")
+	if api_client == null or not api_client.has_method("get_json"):
+		_statusLabel.text = "课程服务不可用"
 		return
+	api_client.call("get_json", API_PATH, _onRequestCompleted, false, REQUEST_TIMEOUT)
 
-	var parsed: Variant = JSON.parse_string(body.get_string_from_utf8())
-	if not parsed is Dictionary:
-		_statusLabel.text = "课程数据解析失败"
-		return
-
-	var payload: Dictionary = parsed as Dictionary
-	if not bool(payload.get("success", true)):
-		_statusLabel.text = str(payload.get("message", "课程加载失败"))
+func _onRequestCompleted(success: bool, payload: Dictionary, error_info: Dictionary) -> void:
+	if not success:
+		_statusLabel.text = str(error_info.get("message", "课程加载失败，请稍后再试"))
 		return
 
 	var data: Variant = payload.get("data", {})