feat: 设置页新增登录管理 TAB

- Session 结构体新增 IP、UserAgent、Remark 字段，登录/注册时记录设备信息
- Store 接口新增 ListByUID、DeleteByUIDExclude 方法，MemoryStore 完整实现
- SessionManager 新增 ListByUID、DestroyOtherByUID、UpdateRemark 方法
- 新增 UA 轻量解析器（session/ua.go），提取浏览器/OS/设备类型
- 新增 settings_api_sessions.go，提供列表/踢出/一键踢出/备注 4 个 API
- 控制器层声明 sessionManager 最小接口（ISP），SettingsController 注入依赖
- Auth 中间件注入 sid 到 gin context，支持识别当前会话
- 设置页左侧导航增加登录管理入口，tab 白名单新增 sessions
- 前端实现设备列表展示（浏览器/OS/设备图标/IP/时间）、当前设备标识、备注输入、踢出按钮、一键踢出
- settings.css 新增会话管理全套样式及响应式适配

internal/session/ua.go

@@ -0,0 +1,97 @@
+package session
+
+import "strings"
+
+// DeviceInfo 从 User-Agent 解析出的设备摘要信息
+type DeviceInfo struct {
+	Device  string // 设备类型：Desktop / Mobile / Tablet
+	OS      string // 操作系统：Windows 10 / macOS / Android 12 等
+	Browser string // 浏览器：Chrome 120 / Firefox 121 / Safari 17 等
+}
+
+// ParseUA 从原始 User-Agent 字符串解析设备信息（轻量级，不引入第三方库）
+func ParseUA(ua string) DeviceInfo {
+	info := DeviceInfo{Device: "Desktop"}
+
+	lower := strings.ToLower(ua)
+
+	// --- 操作系统 ---
+	switch {
+	case strings.Contains(lower, "windows nt 10"):
+		info.OS = "Windows 10/11"
+	case strings.Contains(lower, "windows nt 6.3"):
+		info.OS = "Windows 8.1"
+	case strings.Contains(lower, "windows nt 6.2"):
+		info.OS = "Windows 8"
+	case strings.Contains(lower, "windows nt 6.1"):
+		info.OS = "Windows 7"
+	case strings.Contains(lower, "windows"):
+		info.OS = "Windows"
+	case strings.Contains(lower, "mac os x"):
+		info.OS = "macOS"
+		if strings.Contains(lower, "iphone") {
+			info.OS = "iOS"
+			info.Device = "Mobile"
+		} else if strings.Contains(lower, "ipad") {
+			info.OS = "iPadOS"
+			info.Device = "Tablet"
+		}
+	case strings.Contains(lower, "android"):
+		info.OS = "Android"
+		info.Device = "Mobile"
+		if strings.Contains(lower, "tablet") || strings.Contains(lower, "ipad") {
+			info.Device = "Tablet"
+		}
+	case strings.Contains(lower, "iphone"):
+		info.OS = "iOS"
+		info.Device = "Mobile"
+	case strings.Contains(lower, "ipad"):
+		info.OS = "iPadOS"
+		info.Device = "Tablet"
+	case strings.Contains(lower, "linux"):
+		info.OS = "Linux"
+	case strings.Contains(lower, "cros"):
+		info.OS = "ChromeOS"
+	default:
+		info.OS = "Unknown"
+	}
+
+	// --- 浏览器 ---
+	switch {
+	case strings.Contains(lower, "edg/"):
+		info.Browser = "Edge"
+		info.Browser += extractVersion(ua, "Edg/")
+	case strings.Contains(lower, "chrome/") && !strings.Contains(lower, "edg/"):
+		info.Browser = "Chrome"
+		info.Browser += extractVersion(ua, "Chrome/")
+	case strings.Contains(lower, "firefox/"):
+		info.Browser = "Firefox"
+		info.Browser += extractVersion(ua, "Firefox/")
+	case strings.Contains(lower, "safari/") && !strings.Contains(lower, "chrome/"):
+		info.Browser = "Safari"
+		info.Browser += extractVersion(ua, "Version/")
+	default:
+		info.Browser = "Unknown"
+	}
+
+	return info
+}
+
+// extractVersion 从 UA 中提取主版本号
+func extractVersion(ua, prefix string) string {
+	idx := strings.Index(ua, prefix)
+	if idx == -1 {
+		return ""
+	}
+	rest := ua[idx+len(prefix):]
+	dot := strings.Index(rest, ".")
+	if dot == -1 {
+		// 无点号，取到空格或结尾
+		sp := strings.Index(rest, " ")
+		if sp > 0 {
+			return " " + rest[:sp]
+		}
+		return ""
+	}
+	return " " + rest[:dot]
+}