feat(client): 完成40250客户端核心功能1:1对齐与桥梁高度采样修复

- 桥梁与静态物体高度采样修复：
  - 严格对齐 40250 CMapOutdoor::GetHeight 与 CAttributeInstance::GetHeight
  - 解析 .mdatr 中的 AttributeHeight 网格，使用 is_in_triangle_2d 准确计算桥面多边形平面方程
  - sample_height 查询邻近区块并返回 fMAX(fObjectHeight, fTerrainHeight)，彻底解决走上桥面穿透掉入水底/河床的问题
  - 新增 test_bridge_height_parity.gd 自动化对拍测试
- 40250 怪物击杀经验动效：
  - 1:1 实现 FLY_EXP(0) / FLY_HP / FLY_SP 粒子轨迹与爆炸吸附
- 40250 客户端全系统功能对齐（Batches 1-31）：
  - 包含公会、交易、骑乘、变身、钓鱼、采矿、商城、信件、结婚、地牢等 134 套对拍系统与自动化回归测试
- 文档沉淀：
  - 新增 docs/CLIENT-PARITY-AUDIT-AND-FIX-GUIDE.md 客户端对拍缺陷发现与修复工程指南

project/ui/mouse_controller.gd

@@ -16,6 +16,7 @@ var _attached: Dictionary = {}
 var _targets: Array[Dictionary] = []
 var _touch_index := -1
 var _touch_position := Vector2.ZERO
+var world_drop_handler: Callable
 
 func setup(parent: Node, cursor_manager: Node = null, audio_node: Node = null) -> void:
 	cursor = cursor_manager
@@ -42,6 +43,18 @@ func setup(parent: Node, cursor_manager: Node = null, audio_node: Node = null) -
 	_overlay.add_child(_label)
 	set_process_input(true)
 
+var _drag_started := false
+var _attach_pos := Vector2(-1, -1)
+var _just_attached := false
+
+func _on_attach() -> void:
+	_drag_started = false
+	_just_attached = true
+	if is_inside_tree():
+		_attach_pos = get_viewport().get_mouse_position()
+	else:
+		_attach_pos = Vector2(-1, -1)
+
 func attach_item(window: int, cell: int, vnum: int, count: int,
 		texture: Texture2D = null, source := "inventory", metadata: Dictionary = {},
 		touch_index := -1, touch_position := Vector2(-1, -1)) -> bool:
@@ -69,6 +82,7 @@ func attach_item(window: int, cell: int, vnum: int, count: int,
 	if cursor and cursor.has_method("set_cursor"):
 		cursor.set_cursor(CursorManager.ITEM)
 	_play_ui("pick.wav")
+	_on_attach()
 	return true
 
 func attach_money(amount: int, source := "inventory") -> bool:
@@ -89,12 +103,67 @@ func attach_money(amount: int, source := "inventory") -> bool:
 	if cursor and cursor.has_method("set_cursor"):
 		cursor.set_cursor(CursorManager.ITEM)
 	_play_ui("pick.wav")
+	_on_attach()
+	return true
+
+func attach_skill(skill_id: int, slot_idx: int = 0, texture: Texture2D = null,
+		skill_name := "", touch_index := -1, touch_position := Vector2(-1, -1)) -> bool:
+	if skill_id <= 0:
+		return false
+	_attached = {
+		"source": "skill",
+		"skill_id": skill_id,
+		"slot_idx": slot_idx,
+	}
+	_touch_index = touch_index
+	if touch_position.x >= 0.0 and touch_position.y >= 0.0:
+		_touch_position = touch_position
+	if _icon:
+		_icon.texture = texture
+		_icon.visible = texture != null
+	if _label:
+		_label.text = skill_name if skill_name != "" else "技能 %d" % skill_id
+		_label.visible = true
+	if _overlay:
+		_overlay.visible = true
+	if cursor and cursor.has_method("set_cursor"):
+		cursor.set_cursor(CursorManager.ITEM)
+	_play_ui("pick.wav")
+	_on_attach()
+	return true
+
+func attach_emotion(emote_id: int, texture: Texture2D = null,
+		emote_name := "", touch_index := -1, touch_position := Vector2(-1, -1)) -> bool:
+	if emote_id <= 0:
+		return false
+	_attached = {
+		"source": "emotion",
+		"emote_id": emote_id,
+	}
+	_touch_index = touch_index
+	if touch_position.x >= 0.0 and touch_position.y >= 0.0:
+		_touch_position = touch_position
+	if _icon:
+		_icon.texture = texture
+		_icon.visible = texture != null
+	if _label:
+		_label.text = emote_name if emote_name != "" else "动作 %d" % emote_id
+		_label.visible = true
+	if _overlay:
+		_overlay.visible = true
+	if cursor and cursor.has_method("set_cursor"):
+		cursor.set_cursor(CursorManager.ITEM)
+	_play_ui("pick.wav")
+	_on_attach()
 	return true
 
 func cancel() -> void:
 	_attached.clear()
 	_touch_index = -1
 	_touch_position = Vector2.ZERO
+	_drag_started = false
+	_attach_pos = Vector2(-1, -1)
+	_just_attached = false
 	if _overlay:
 		_overlay.visible = false
 	if cursor and cursor.has_method("reset"):
@@ -128,47 +197,132 @@ func _process(_dt: float) -> void:
 		if c == null or not is_instance_valid(c):
 			_targets.remove_at(i)
 
+func _set_handled() -> void:
+	var vp := get_viewport()
+	if vp:
+		vp.set_input_as_handled()
+
 func _input(event: InputEvent) -> void:
 	if not is_attached():
 		return
 	if event is InputEventKey and event.pressed and event.keycode == KEY_ESCAPE:
 		cancel()
-		get_viewport().set_input_as_handled()
+		_set_handled()
 		return
 	if event is InputEventMouseButton and event.pressed and event.button_index == MOUSE_BUTTON_RIGHT:
 		cancel()
-		get_viewport().set_input_as_handled()
+		_set_handled()
 		return
-	if event is InputEventMouseButton and not event.pressed and event.button_index == MOUSE_BUTTON_LEFT:
-		_drop_at(event.position)
-		get_viewport().set_input_as_handled()
+	if event is InputEventMouseMotion:
+		if _attach_pos.x >= 0.0 and (_attach_pos - event.position).length() > 6.0:
+			_drag_started = true
 		return
+	if event is InputEventMouseButton and event.button_index == MOUSE_BUTTON_LEFT:
+		if event.pressed:
+			# If user already picked up an item and left-clicks on a target:
+			if not _just_attached:
+				if _drop_at(event.position):
+					_set_handled()
+					return
+				# If clicked outside any target, cancel attachment
+				if _attach_pos.x >= 0.0 and (_attach_pos - event.position).length() > 6.0:
+					_play_ui("loginfail.wav")
+					cancel()
+					_set_handled()
+					return
+		else:
+			# Left mouse release (not pressed)
+			_just_attached = false
+			# If dragged, attempt drop at release position
+			if _drag_started or (_attach_pos.x >= 0.0 and (_attach_pos - event.position).length() > 8.0):
+				_drop_at(event.position)
+				_set_handled()
+				return
+			# If not dragged (clicked to pick up), keep item attached to cursor!
+			return
 	if event is InputEventScreenDrag and event.index == _touch_index:
 		_touch_position = event.position
-		get_viewport().set_input_as_handled()
+		_set_handled()
 		return
 	if event is InputEventScreenTouch and not event.pressed and event.index == _touch_index:
 		_touch_position = event.position
 		_drop_at(event.position)
-		get_viewport().set_input_as_handled()
+		_set_handled()
 
-func _drop_at(position: Vector2) -> void:
+func _drop_at(position: Vector2) -> bool:
 	var payload := attached()
+	if payload.is_empty():
+		return false
+
+	var icon_center := position + Vector2(24, 24)
+	var best_idx := -1
+	var best_dist := 999999.0
+
+	# Pass 1: exact hit test (cursor position or icon center)
 	for i in range(_targets.size() - 1, -1, -1):
 		var c: Control = _targets[i].get("control", null)
 		if c == null or not is_instance_valid(c):
 			_targets.remove_at(i)
 			continue
-		if not c.visible or not c.get_global_rect().has_point(position):
+		if not c.visible:
 			continue
-		var cb: Callable = _targets[i].get("callback", Callable())
-		if cb.is_valid() and bool(cb.call(payload)):
+		var rect := c.get_global_rect()
+		if rect.has_point(position):
+			var d := position.distance_to(rect.get_center())
+			if d < best_dist:
+				best_dist = d
+				best_idx = i
+		elif rect.has_point(icon_center):
+			var d := icon_center.distance_to(rect.get_center())
+			if d < best_dist:
+				best_dist = d
+				best_idx = i
+
+	# Pass 2: generous hit test with 16px tolerance margin
+	if best_idx < 0:
+		for i in range(_targets.size() - 1, -1, -1):
+			var c: Control = _targets[i].get("control", null)
+			if c == null or not is_instance_valid(c) or not c.visible:
+				continue
+			var rect := c.get_global_rect().grow(16.0)
+			if rect.has_point(position):
+				var d := position.distance_to(rect.get_center())
+				if d < best_dist:
+					best_dist = d
+					best_idx = i
+			elif rect.has_point(icon_center):
+				var d := icon_center.distance_to(rect.get_center())
+				if d < best_dist:
+					best_dist = d
+					best_idx = i
+
+	if best_idx >= 0:
+		var cb: Callable = _targets[best_idx].get("callback", Callable())
+		if cb.is_valid():
+			var ok := false
+			if cb.get_argument_count() >= 2:
+				ok = bool(cb.call(payload, position))
+			else:
+				ok = bool(cb.call(payload))
+			if ok:
+				_play_ui("drop.wav")
+				cancel()
+				return true
+
+	if world_drop_handler.is_valid():
+		var ok := false
+		if world_drop_handler.get_argument_count() >= 2:
+			ok = bool(world_drop_handler.call(payload, position))
+		else:
+			ok = bool(world_drop_handler.call(payload))
+		if ok:
 			_play_ui("drop.wav")
 			cancel()
-			return
-	# 与参考端释放到无效区域的取消语义一致。
+			return true
+
 	_play_ui("loginfail.wav")
 	cancel()
+	return false
 
 func _play_ui(name: String) -> void:
 	if audio and audio.has_method("play_ui"):