feat(FE-65): enhance MovementForm to support file uploads with FormData conversion

src/lib/form-data.ts

@@ -0,0 +1,45 @@
+export function toFormData(
+  value: unknown,
+  form = new FormData(),
+  parentKey?: string
+) {
+  if (value === undefined || value === null) {
+    if (parentKey) form.append(parentKey, '');
+    return form;
+  }
+
+  if (value instanceof File) {
+    if (!parentKey) throw new Error('File must have a key');
+    form.append(parentKey, value);
+    return form;
+  }
+
+  if (Array.isArray(value)) {
+    value.forEach((v, i) => {
+      const key = parentKey ? `${parentKey}[${i}]` : `${i}`;
+      toFormData(v, form, key);
+    });
+    return form;
+  }
+
+  if (typeof value === 'object') {
+    Object.entries(value as Record<string, unknown>).forEach(([k, v]) => {
+      const key = parentKey ? `${parentKey}[${k}]` : k;
+      toFormData(v, form, key);
+    });
+    return form;
+  }
+
+  if (parentKey) form.append(parentKey, String(value));
+  return form;
+}
+
+export function containsFile(obj: unknown): boolean {
+  if (!obj) return false;
+  if (obj instanceof File) return true;
+  if (Array.isArray(obj)) return obj.some(containsFile);
+  if (typeof obj === 'object') {
+    return Object.values(obj as Record<string, unknown>).some(containsFile);
+  }
+  return false;
+}