fix: replace unguarded crypto.randomUUID() with safe generateUUID() utility

lib/calendar-participants.ts

@@ -1,4 +1,5 @@
 import type { CalendarEvent, CalendarParticipant } from '@/lib/jmap/types';
+import { generateUUID } from '@/lib/utils';
 
 export interface ParticipantInfo {
   id: string;
@@ -104,9 +105,7 @@ export function buildParticipantMap(
 ): Record<string, Partial<CalendarParticipant>> {
   const participants: Record<string, Partial<CalendarParticipant>> = {};
 
-  const generateId = () => typeof crypto !== 'undefined' && crypto.randomUUID
-    ? crypto.randomUUID()
-    : `p-${Date.now()}-${Math.random().toString(36).slice(2, 9)}`;
+  const generateId = () => generateUUID();
 
   participants[generateId()] = {
     '@type': 'Participant',

lib/smime/mime-builder.ts

@@ -5,6 +5,8 @@
  * All line endings are CRLF per RFC 5322.
  */
 
+import { generateUUID } from '@/lib/utils';
+
 const CRLF = '\r\n';
 
 export interface MimeAttachment {
@@ -43,7 +45,7 @@ export function buildMimeMessage(input: MimeMessageInput): Uint8Array {
   // BCC is intentionally omitted from the MIME headers per RFC 5322
   lines.push(formatHeader('Subject', encodeHeaderValue(input.subject)));
   lines.push(formatHeader('Date', formatDate(input.date ?? new Date())));
-  lines.push(formatHeader('Message-ID', input.messageId ?? `<${crypto.randomUUID()}@smime.local>`));
+  lines.push(formatHeader('Message-ID', input.messageId ?? `<${generateUUID()}@smime.local>`));
   if (input.inReplyTo) {
     lines.push(formatHeader('In-Reply-To', input.inReplyTo));
   }
@@ -245,7 +247,7 @@ export function wrapCmsAsSmimeMessage(cmsBlob: Blob | ArrayBuffer | Uint8Array,
   }
   lines.push(formatHeader('Subject', encodeHeaderValue(input.subject)));
   lines.push(formatHeader('Date', formatDate(input.date ?? new Date())));
-  lines.push(formatHeader('Message-ID', input.messageId ?? `<${crypto.randomUUID()}@smime.local>`));
+  lines.push(formatHeader('Message-ID', input.messageId ?? `<${generateUUID()}@smime.local>`));
   if (input.inReplyTo) {
     lines.push(formatHeader('In-Reply-To', input.inReplyTo));
   }

lib/smime/pkcs12-import.ts

@@ -1,5 +1,6 @@
 import * as asn1js from 'asn1js';
 import * as pkijs from 'pkijs';
+import { generateUUID } from '@/lib/utils';
 import {
   extractCertificateInfo,
   classifyCapabilities,
@@ -154,7 +155,7 @@ export async function importPkcs12(
   const email = certInfo.emailAddresses[0] ?? '';
 
   const keyRecord: SmimeKeyRecord = {
-    id: crypto.randomUUID(),
+    id: generateUUID(),
     email: email.toLowerCase(),
     certificate: leafCertDer,
     certificateChain: chainCertsDer,

lib/template-utils.ts

@@ -1,6 +1,7 @@
 import DOMPurify from 'dompurify';
 import type { EmailTemplate } from './template-types';
 import { BUILT_IN_PLACEHOLDERS } from './template-types';
+import { generateUUID } from './utils';
 
 const PLACEHOLDER_REGEX = /\{\{(\w+)\}\}/g;
 const MAX_TEMPLATE_NAME_LENGTH = 200;
@@ -149,7 +150,7 @@ export function importTemplates(json: string): ImportResult {
     const recipients = t.defaultRecipients as Record<string, unknown> | undefined;
 
     templates.push({
-      id: crypto.randomUUID(),
+      id: generateUUID(),
       name: sanitizeText(t.name),
       subject: sanitizeText(t.subject),
       body: sanitizeText(t.body),

lib/utils.ts

@@ -7,6 +7,13 @@ export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs));
 }
 
+export function generateUUID(): string {
+  if (typeof crypto !== 'undefined' && typeof crypto.randomUUID === 'function') {
+    return crypto.randomUUID();
+  }
+  return `${Date.now()}-${Math.random().toString(36).slice(2, 11)}`;
+}
+
 export function formatDate(date: Date | string): string {
   const d = typeof date === "string" ? new Date(date) : date;
   const now = new Date();

lib/vcard.ts

@@ -1,4 +1,5 @@
 import type { ContactCard, NameComponent, ContactOnlineService, AnniversaryDate, PartialDate } from "@/lib/jmap/types";
+import { generateUUID } from "@/lib/utils";
 
 // Convert RFC 9553 AnniversaryDate (PartialDate|Timestamp|string) to vCard date string
 function anniversaryDateToVcardString(date: AnniversaryDate): string {
@@ -153,7 +154,7 @@ export function parseVCard(vcfString: string): ContactCard[] {
 }
 
 function buildContact(raw: Record<string, string[]>): ContactCard | null {
-  const id = `import-${crypto.randomUUID()}`;
+  const id = `import-${generateUUID()}`;
   const card: ContactCard = { id, addressBookIds: {} };
 
   for (const [fullKey, values] of Object.entries(raw)) {