fix: create agent dir before checking binary; add runtime deps to deploy docs

scripts/deploy.sh

@@ -545,6 +545,9 @@ cmd_install_agent() {
     echo -e "${BLUE}[2/5] 安装 Agent...${NC}"
     resolve_agent_token
     
+    mkdir -p "$AGENT_INSTALL_DIR"
+    mkdir -p "/var/lib/safesight-edge-agent"
+
     # 查找 Agent 编译产物（优先使用预编译的 arm64 二进制）
     AGENT_SOURCE=""
     # 离线包模式优先：二进制在脚本同目录
@@ -567,9 +570,6 @@ cmd_install_agent() {
         return
     fi
 
-    mkdir -p "$AGENT_INSTALL_DIR"
-    mkdir -p "/var/lib/safesight-edge-agent"
-    
     cp "$AGENT_SOURCE" "$AGENT_INSTALL_DIR/safesight-edge-agent"
     chmod +x "$AGENT_INSTALL_DIR/safesight-edge-agent"
     printf '%s\n' "$AGENT_TOKEN" > "$AGENT_TOKEN_FILE"