feat(ios): 添加远端视频录制功能并优化信令连接稳定性

- 新增 VideoRecorder 组件，支持 WebRTC 和自编码两种模式录制远端视频为 MP4
- 优化 SignalingClient 连接管理，修复 WebSocket 握手前 receive 导致的断开问题
- 重构控制面板 UI，支持统计信息折叠展开和录制控制按钮
- 添加录制状态指示、保存路径提示及断开自动取消录制逻辑
- 更新项目配置和文档，补充录制功能说明

webrtc_controller_ios/web_rtc_controller_ios.xcodeproj/project.pbxproj

@@ -23,6 +23,7 @@
 		FB000000000000000000000E /* DeviceUtils.swift in Sources */ = {isa = PBXBuildFile; fileRef = FA000000000000000000000E /* DeviceUtils.swift */; };
 		FB000000000000000000000F /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = FA000000000000000000000F /* Assets.xcassets */; };
 		FB0000000000000000000010 /* WebRTC in Frameworks */ = {isa = PBXBuildFile; productRef = FE0000000000000000000002 /* WebRTC */; };
+		FB0000000000000000000012 /* VideoRecorder.swift in Sources */ = {isa = PBXBuildFile; fileRef = FA0000000000000000000012 /* VideoRecorder.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
@@ -43,6 +44,7 @@
 		FA000000000000000000000F /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		FA0000000000000000000010 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		FA0000000000000000000011 /* web_rtc_controller_ios.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = web_rtc_controller_ios.app; sourceTree = BUILT_PRODUCTS_DIR; };
+		FA0000000000000000000012 /* VideoRecorder.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = VideoRecorder.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -120,6 +122,7 @@
 			children = (
 				FA0000000000000000000006 /* WebRTCClient.swift */,
 				FA0000000000000000000007 /* SelfCodecDecoder.swift */,
+				FA0000000000000000000012 /* VideoRecorder.swift */,
 			);
 			path = WebRTC;
 			sourceTree = "<group>";
@@ -183,7 +186,7 @@
 			attributes = {
 				BuildIndependentTargetsInParallel = 1;
 				LastSwiftUpdateCheck = 1500;
-				LastUpgradeCheck = 1500;
+				LastUpgradeCheck = 2630;
 				TargetAttributes = {
 					FD0000000000000000000002 = {
 						CreatedOnToolsVersion = 15.0;
@@ -235,6 +238,7 @@
 				FB0000000000000000000005 /* ControlMessage.swift in Sources */,
 				FB0000000000000000000006 /* WebRTCClient.swift in Sources */,
 				FB0000000000000000000007 /* SelfCodecDecoder.swift in Sources */,
+				FB0000000000000000000012 /* VideoRecorder.swift in Sources */,
 				FB0000000000000000000008 /* RemoteTouchView.swift in Sources */,
 				FB0000000000000000000009 /* RemoteVideoView.swift in Sources */,
 				FB000000000000000000000A /* SelfCodecDisplayView.swift in Sources */,
@@ -253,6 +257,7 @@
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				ASSETCATALOG_COMPILER_GENERATE_SWIFT_ASSET_SYMBOL_EXTENSIONS = YES;
+				CLANG_ANALYZER_LOCALIZABILITY_NONLOCALIZED = YES;
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++20";
@@ -306,6 +311,7 @@
 				MTL_FAST_MATH = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = iphoneos;
+				STRING_CATALOG_GENERATE_SYMBOLS = YES;
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = "DEBUG $(inherited)";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
 			};
@@ -316,6 +322,7 @@
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				ASSETCATALOG_COMPILER_GENERATE_SWIFT_ASSET_SYMBOL_EXTENSIONS = YES;
+				CLANG_ANALYZER_LOCALIZABILITY_NONLOCALIZED = YES;
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++20";
@@ -362,6 +369,7 @@
 				MTL_ENABLE_DEBUG_INFO = NO;
 				MTL_FAST_MATH = YES;
 				SDKROOT = iphoneos;
+				STRING_CATALOG_GENERATE_SYMBOLS = YES;
 				SWIFT_COMPILATION_MODE = wholemodule;
 				VALIDATE_PRODUCT = YES;
 			};
@@ -444,8 +452,8 @@
 			repositoryURL = "https://github.com/stasel/WebRTC.git";
 			requirement = {
 				kind = versionRange;
-				minimumVersion = 120.0.0;
 				maximumVersion = 200.0.0;
+				minimumVersion = 120.0.0;
 			};
 		};
 /* End XCRemoteSwiftPackageReference section */