Fix CSV header whitespace causing exact match to fail

Trim CSV headers and row values in fetch_remote_csv_data() to prevent
whitespace in column names (e.g. "OTP ") from breaking the validation
lookup against sanitized field config keys.

includes/class-Shortcode.php

@@ -529,8 +529,8 @@ class CHECKER_SHORTCODE extends SHEET_DATA_CHECKER_PRO
             return $data;
         }
 
-        // Get headers from first line
-        $keys = str_getcsv($lines[0], $delimiter);
+        // Get headers from first line (trim to handle whitespace in column names)
+        $keys = array_map('trim', str_getcsv($lines[0], $delimiter));
 
         // Process data rows
         $count = 0;
@@ -539,7 +539,7 @@ class CHECKER_SHORTCODE extends SHEET_DATA_CHECKER_PRO
                 continue; // Skip empty lines
             }
 
-            $row = str_getcsv($lines[$i], $delimiter);
+            $row = array_map('trim', str_getcsv($lines[$i], $delimiter));
             if (count($keys) === count($row)) {
                 $data[] = array_combine($keys, $row);
                 $count++;