Harden campaign import handling

webui/src/features/campaigns/utils/bulkImport.ts

@@ -749,9 +749,22 @@ function parseAddress(value: string): ImportedAddress {
 }
 
 function splitCell(value: string, separators: string): string[] {
-  const escaped = separators.split("").map((char) => char.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")).join("");
-  if (!escaped) return [value.trim()].filter(Boolean);
-  return value.split(new RegExp(`[${escaped}]+`)).map((item) => item.trim()).filter(Boolean);
+  const separatorSet = new Set(separators.split(""));
+  if (separatorSet.size === 0) return [value.trim()].filter(Boolean);
+  const items: string[] = [];
+  let current = "";
+  for (const char of value) {
+    if (separatorSet.has(char)) {
+      const trimmed = current.trim();
+      if (trimmed) items.push(trimmed);
+      current = "";
+      continue;
+    }
+    current += char;
+  }
+  const trimmed = current.trim();
+  if (trimmed) items.push(trimmed);
+  return items;
 }
 
 function parseOptionalBoolean(value: string, fallback: boolean): boolean {