feat: complete mobile UI implementation

project/ui/quest_log.gd

@@ -42,6 +42,7 @@ var _quest_button_order: Array[int] = []   # 最新在前：BINARY_RecvQuest 的
 var _party_shown := false
 var _party_probe: Callable = Callable()
 var _screen_size_override := Vector2.ZERO   # >0 时覆盖 viewport 尺寸（离线回归用）
+var _mobile_mode := false
 var _clock_remaining: Dictionary = {}
 var _clock_labels: Dictionary = {}
 var _clock_accumulator := 0.0
@@ -66,6 +67,9 @@ func set_item_sources(proto_node: Node, item_list: RefCounted, assets_root: Stri
 func is_open() -> bool:
 	return _root != null and _root.visible
 
+func get_mobile_window() -> Control:
+	return _root
+
 func close() -> void:
 	if _root:
 		_root.visible = false
@@ -120,6 +124,13 @@ func set_party_shown(shown: bool) -> void:
 	_party_shown = shown
 	_refresh_quest_buttons()
 
+# MobileHud supplies one compact task entry at the right side of the
+# landscape HUD.  Keep the quest-letter data here, but hide the desktop
+# absolute-positioned buttons while mobile mode is active.
+func set_mobile_mode(enabled: bool) -> void:
+	_mobile_mode = enabled
+	_update_button_visibility()
+
 func set_screen_size_override(size: Vector2) -> void:
 	_screen_size_override = size
 	_refresh_quest_buttons()
@@ -425,4 +436,5 @@ func _start_quest(index: int) -> void:
 
 func _update_button_visibility() -> void:
 	if _button_root:
-		_button_root.visible = _quest_buttons_visible and not _quest_buttons_suppressed and not _quest_button_data.is_empty()
+		_button_root.visible = not _mobile_mode and _quest_buttons_visible \
+				and not _quest_buttons_suppressed and not _quest_button_data.is_empty()