chore: added filename extension check (#1106)

**Description:**

This PR adds a check for filename title and if the title ends with
`.pdf` then the extension isnt added or else its added

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit


- **Bug Fixes**
- Enhanced email attachment handling to ensure PDF files are correctly
identified with a ".pdf" extension.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/lib/server-only/document/send-completed-email.ts

@@ -80,7 +80,7 @@ export const sendCompletedEmail = async ({ documentId, requestMetadata }: SendDo
       text: render(template, { plainText: true }),
       attachments: [
         {
-          filename: document.title,
+          filename: document.title.endsWith('.pdf') ? document.title : document.title + '.pdf',
           content: Buffer.from(completedDocument),
         },
       ],
@@ -130,7 +130,7 @@ export const sendCompletedEmail = async ({ documentId, requestMetadata }: SendDo
         text: render(template, { plainText: true }),
         attachments: [
           {
-            filename: document.title,
+            filename: document.title.endsWith('.pdf') ? document.title : document.title + '.pdf',
             content: Buffer.from(completedDocument),
           },
         ],