fix: 确保ListAll返回空切片而非nil

- 修复Linux/macOS/Windows平台的ListAll实现
- 使用make([]ProcessInfo, 0)初始化切片
- 避免在无进程时返回nil导致测试失败

Author: TNT-Likely

pkg/port/darwin.go

@@ -129,7 +129,7 @@ func (m *DarwinManager) ListAll() ([]ProcessInfo, error) {
 // parseLsofOutput 解析 lsof 输出
 func (m *DarwinManager) parseLsofOutput(output string) ([]ProcessInfo, error) {
 	lines := strings.Split(output, "\n")
-	var processes []ProcessInfo
+	processes := make([]ProcessInfo, 0)
 	seenPorts := make(map[string]bool) // 用于去重 (port+pid)
 
 	for _, line := range lines {

pkg/port/linux.go

@@ -175,7 +175,7 @@ func (m *LinuxManager) listAllWithNetstat() ([]ProcessInfo, error) {
 // parseSSOutput 解析 ss 命令输出
 func (m *LinuxManager) parseSSOutput(output string) ([]ProcessInfo, error) {
 	lines := strings.Split(output, "\n")
-	var processes []ProcessInfo
+	processes := make([]ProcessInfo, 0)
 	seenPorts := make(map[string]bool)
 
 	for _, line := range lines {
@@ -258,7 +258,7 @@ func (m *LinuxManager) parseSSOutput(output string) ([]ProcessInfo, error) {
 // parseNetstatOutput 解析 netstat 命令输出
 func (m *LinuxManager) parseNetstatOutput(output string) ([]ProcessInfo, error) {
 	lines := strings.Split(output, "\n")
-	var processes []ProcessInfo
+	processes := make([]ProcessInfo, 0)
 	seenPorts := make(map[string]bool)
 
 	for _, line := range lines {

pkg/port/windows.go

@@ -137,7 +137,7 @@ func (m *WindowsManager) ListAll() ([]ProcessInfo, error) {
 // parseNetstatOutput 解析 netstat 命令输出
 func (m *WindowsManager) parseNetstatOutput(output string) ([]ProcessInfo, error) {
 	lines := strings.Split(output, "\n")
-	var processes []ProcessInfo
+	processes := make([]ProcessInfo, 0)
 	seenPorts := make(map[string]bool) // 用于去重 (port+pid)
 
 	for _, line := range lines {