feat(auth): add logout functionality

- Implement LogoutHandler to handle user logout requests
- Add DeleteTokenInfo and GetUserIDFromToken functions to auth module
- Update README.md with logout endpoint documentation

userAct.go

@@ -159,3 +159,32 @@ func LoginHandler(w http.ResponseWriter, r *http.Request) {
 	})
 	postLog.Info(fmt.Sprintf("[LoginHandler] User \"%s\" Login successful", req.Username))
 }
+
+func LogoutHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		SendErrorResponse(w, http.StatusMethodNotAllowed, "Invalid request method")
+		postLog.Warning(fmt.Sprintf("[LogoutHandler] Invalid request method: %s", r.Method))
+		return
+	}
+
+	if !ValidateTimeStamp(r.Header) {
+		SendErrorResponse(w, http.StatusBadRequest, "Invalid or missing X-Timestamp in header")
+		return
+	}
+
+	userID, err := GetUserIDFromToken(r.Header.Get("X-Token"))
+	if err != nil {
+		SendErrorResponse(w, http.StatusUnauthorized, "Invalid or missing token")
+		postLog.Warning(fmt.Sprintf("[LogoutHandler] Invalid or missing token: %v", err))
+		return
+	}
+
+	if err := DeleteTokenInfo(userID); err != nil {
+		SendErrorResponse(w, http.StatusInternalServerError, "Failed to logout")
+		postLog.Error(fmt.Sprintf("[LogoutHandler] Failed to logout user [%d]%s: %v", userID, GetUsernameByID(userID), err))
+		return
+	}
+
+	SendSuccessResponse(w, "Logout successful", nil)
+	postLog.Info(fmt.Sprintf("[LogoutHandler] User [%d]%s Logout successful", userID, GetUsernameByID(userID)))
+}