refactor: consolidate debug flag and update gitignore

- Rename debugMode to isDebug for consistency across codebase
- Move debug flag check in ValidateTimeStamp to match other validations
- Add database.db to gitignore and remove unused config file
- Update README.md to clarify user registration rules

handlers.go

@@ -35,6 +35,7 @@ func RegisterHandler(w http.ResponseWriter, r *http.Request) {
 
 	if !ValidateTimeStamp(r.Header) {
 		SendErrorResponse(w, http.StatusBadRequest, "Invalid or missing X-Timestamp in header")
+		postLog.Warning(fmt.Sprintf("[RegisterHandler] Invalid or missing X-Timestamp in header: %s", r.Header.Get("X-Timestamp")))
 		return
 	}
 
@@ -219,8 +220,10 @@ func ValidateRequestWithBody(w http.ResponseWriter, r *http.Request, body []byte
 		return 0, "", fmt.Errorf("Token is required in header: %s", token)
 	}
 
-	if !ValidateTimeStamp(r.Header) {
-		return 0, "", fmt.Errorf("Invalid or missing X-Timestamp in header")
+	if !isDebug {
+		if !ValidateTimeStamp(r.Header) {
+			return 0, "", fmt.Errorf("Invalid or missing X-Timestamp in header")
+		}
 	}
 
 	userID, err := extractUserIDFromToken(token)
@@ -247,8 +250,10 @@ func ValidateRequestWithHeader(w http.ResponseWriter, r *http.Request, requiredF
 		return 0, "", fmt.Errorf("Token is required in header: %s", token)
 	}
 
-	if !ValidateTimeStamp(r.Header) {
-		return 0, "", fmt.Errorf("Invalid or missing X-Timestamp in header")
+	if !isDebug {
+		if !ValidateTimeStamp(r.Header) {
+			return 0, "", fmt.Errorf("Invalid or missing X-Timestamp in header")
+		}
 	}
 
 	userID, err := extractUserIDFromToken(token)