fix: 修复聊天系统编译错误

- 修复 WebSocketManager/SocketIOClient 函数缩进错误
- 重命名 is_connected() 避免与 Object 基类冲突
- 修复 tscn 文件多余前导空格
- 修复测试文件 GUT 断言函数调用
- 添加 GUT 测试框架

addons/gut/fonts/AnonymousPro-BoldItalic.ttf.import

@@ -0,0 +1,36 @@
+[remap]
+
+importer="font_data_dynamic"
+type="FontFile"
+uid="uid://msst1l2s2s"
+path="res://.godot/imported/AnonymousPro-BoldItalic.ttf-4274bf704d3d6b9cd32c4f0754d8c83d.fontdata"
+
+[deps]
+
+source_file="res://addons/gut/fonts/AnonymousPro-BoldItalic.ttf"
+dest_files=["res://.godot/imported/AnonymousPro-BoldItalic.ttf-4274bf704d3d6b9cd32c4f0754d8c83d.fontdata"]
+
+[params]
+
+Rendering=null
+antialiasing=1
+generate_mipmaps=false
+disable_embedded_bitmaps=true
+multichannel_signed_distance_field=false
+msdf_pixel_range=8
+msdf_size=48
+allow_system_fallback=true
+force_autohinter=false
+modulate_color_glyphs=false
+hinting=1
+subpixel_positioning=1
+keep_rounding_remainders=true
+oversampling=0.0
+Fallbacks=null
+fallbacks=[]
+Compress=null
+compress=true
+preload=[]
+language_support={}
+script_support={}
+opentype_features={}