2V0-f: run the real system.py app loop in Godot

- system.py runs app.Loop() on the script fiber; each UIUpdate is one
  CPythonApplication::Process(). Logo -> Login, popup ESC/click and
  app.Exit teardown (launcher cleared first, as in 40250 Main) work.
- Image commands are base-texture quads with UVs (a .sub shares its parent
  texture); ImageInstance/ExpandedImageInstance OnRender and SetRenderingRect
  ported verbatim, so scale/rotation/rendering rect are drawn.
- CGraphicBase::GetColor / grp.GenerateColor ported (ThinBoard background).
- port.app_loop test, python_host_test app-loop checks, MT_TEST_MODE=python_ui.
- TODO: .fnt/CGraphicText font pipeline, ExpandedImage blend modes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

project/python_host_check.gd

@@ -3,7 +3,8 @@
 # 和 ctest 的 `port.python_launcher` 跑的是同一条序列，区别只有一个：那边是独立可执行文件，这边在
 # Godot 进程里，由 GDScript 发起 —— step 4 要验的就是这个差别。2V0 把 C++ 模块注册上之前，
 # 2V0-e 的玩法桩让 system.py 真正走到 prototype.RunApp()；
-# 2V0-f 的应用 adapter 尚未创建图形设备，RunApp 捕获 CREATE_DEVICE 并给出原版提示。
+# 没设画布尺寸时 app.Create 没有设备，RunApp 捕获 CREATE_DEVICE 并给出原版提示；设了尺寸以后
+# system.py 停在 app.Loop() 里，由 ui_update 逐帧推进（_run_app_loop）。
 #
 # 真机上通常没有 40250 的 Client/pack（APK 里只有 python27.zip），所以分两段：解释器 + 标准库这一段
 # 不需要 pack，任何平台都跑；system.py 这一段需要 pack，没有就跳过并说清楚。
@@ -119,6 +120,16 @@ wndMgr.Show(_ui_clip)
 		var segment: PackedVector2Array = surface._clip_line(Vector2(-10, 10), Vector2(50, 10), Rect2(0, 0, 30, 30))
 		_ck(segment.size() == 2 and segment[0] == Vector2(0, 10) and segment[1] == Vector2(30, 10),
 				"Godot Canvas 线段裁剪保留可见区间")
+		# ExpandedImage 的四边形（TL, TR, BL, BR）被 viewport 裁掉右半边，UV 随位置按仿射关系重算。
+		var quad := PackedVector2Array([Vector2(0, 0), Vector2(20, 0), Vector2(0, 10), Vector2(20, 10)])
+		var quad_uv := PackedVector2Array([Vector2(0, 0), Vector2(1, 0), Vector2(0, 1), Vector2(1, 1)])
+		var clipped: Array = surface._clip_quad(quad, quad_uv, Rect2(0, 0, 10, 10))
+		var max_u := 0.0
+		for i in clipped[1].size():
+			max_u = maxf(max_u, clipped[1][i].x)
+			if not is_equal_approx(clipped[1][i].x, clipped[0][i].x / 20.0):
+				max_u = -1.0
+		_ck(clipped[0].size() >= 3 and is_equal_approx(max_u, 0.5), "ExpandedImage 四边形裁剪后 UV 同步收缩")
 		surface.free()
 		_ck(Metin2PythonHost.run_line("wndMgr.Destroy(_ui_bar)") == "", "Bar 窗口已销毁")
 		_ck(Metin2PythonHost.run_line("grp.RestoreViewport(); wndMgr.Destroy(_ui_clip)") == "", "裁剪窗口已销毁")
@@ -159,4 +170,39 @@ wndMgr.Show(_ui_clip)
 
 	Metin2PythonHost.stop()
 	_ck(not Metin2PythonHost.is_running(), "stop() 之后 is_running() 为假")
+	if has_pack:
+		_run_app_loop()
 	return fail
+
+# 2V0-f：有画布尺寸时 app.Create 成功，system.py 停在 app.Loop() 里（脚本线程），每次 ui_update 就是
+# 一次 CPythonApplication::Process()。Logo 阶段 → LoginWindow → 弹窗 ESC 关闭 → stop 走完 RunApp 收尾。
+func _run_app_loop() -> void:
+	_ck(Metin2PythonHost.start("") == "", "第二次 start()")
+	Metin2PythonHost.set_ui_size(800, 600)
+	var err: String = Metin2PythonHost.run_main_script("")
+	_ck(err == "", "system.py 进入 app.Loop()：" + err)
+	_ck(Metin2PythonHost.is_app_looping(), "is_app_looping() 为真")
+	_ck(Metin2PythonHost.run_line("import __main__, gc, networkModule, introLogo\n__main__._stream = [o for o in gc.get_objects() if isinstance(o, networkModule.MainStream)][0]\nassert isinstance(_stream.curPhaseWindow, introLogo.LogoWindow)") == "",
+			"Logo 阶段已打开")
+	var reached := false
+	for i in 600:
+		if not Metin2PythonHost.is_app_looping():
+			break
+		Metin2PythonHost.ui_update()
+		if Metin2PythonHost.run_line("import introLogin\nif not isinstance(_stream.curPhaseWindow, introLogin.LoginWindow): raise SystemError") == "":
+			reached = true
+			break
+	_ck(reached, "帧推进后进入 LoginWindow")
+	_ck(Metin2PythonHost.run_line("_stream.popupWindow.Open('POPUP_PROBE')\nassert _stream.popupWindow.IsShow()") == "", "PopupDialog 已打开")
+	Metin2PythonHost.ui_update()
+	var has_popup := false
+	for draw in Metin2PythonHost.ui_render_commands():
+		if draw["kind"] == "text" and draw["text"] == "POPUP_PROBE":
+			has_popup = true
+	_ck(has_popup, "弹窗文字进入 Godot Canvas 命令队列")
+	Metin2PythonHost.ui_key(1, true) # DIK_ESCAPE
+	Metin2PythonHost.ui_key(1, false)
+	Metin2PythonHost.ui_update()
+	_ck(Metin2PythonHost.run_line("assert not _stream.popupWindow.IsShow()") == "", "ESC 关闭弹窗")
+	Metin2PythonHost.stop()
+	_ck(not Metin2PythonHost.is_running() and not Metin2PythonHost.is_app_looping(), "stop() 结束 app.Loop() 并收尾")