Feat: Implement H264 for Linux client with dynamic libx264 loading

common/PTYHandler.h

@@ -202,6 +202,8 @@ private:
             // macOS locale settings
             setenv("LANG", "en_US.UTF-8", 1);
             setenv("LC_ALL", "en_US.UTF-8", 1);
+            // Disable zsh session save/restore (causes errors in PTY)
+            setenv("SHELL_SESSIONS_DISABLE", "1", 1);
 
             // Try zsh first (macOS default), fallback to bash
             if (access("/bin/zsh", X_OK) == 0) {

common/commands.h

@@ -1048,6 +1048,14 @@ enum QualityLevel {
     QUALITY_COUNT   = 6,
 };
 
+// 屏幕压缩算法常量 (所有平台共用)
+#ifndef ALGORITHM_GRAY
+#define ALGORITHM_GRAY    0   // 灰度压缩
+#define ALGORITHM_DIFF    1   // 差分压缩 (BGRA)
+#define ALGORITHM_H264    2   // H264 硬件编码
+#define ALGORITHM_RGB565  3   // RGB565 压缩
+#endif
+
 /* 质量配置(与 QualityLevel 对应)
 - strategy = 0：1080p 限制
 - strategy = 1：原始分辨率