Update privacy policy link in website footer (#557)

Replaces the hardcoded privacy statement URL in the footer with the
Microsoft short-link redirect.

## Changes
- **`www/src/lib/components/home/footer.svelte`**: Updated `href` from
`https://www.microsoft.com/en-us/privacy/privacystatement` →
`https://go.microsoft.com/fwlink/?LinkId=521839`

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: MaanavD <24942306+MaanavD@users.noreply.github.com>

Author: Copilot

www/src/lib/components/home/footer.svelte

@@ -111,7 +111,7 @@
 					© {new Date().getFullYear()} Microsoft Corporation. All rights reserved.
 				</p>
 				<a
-					href="https://www.microsoft.com/en-us/privacy/privacystatement"
+					href="https://go.microsoft.com/fwlink/?LinkId=521839"
 					target="_blank"
 					rel="noopener noreferrer"
 					class="text-sm text-muted-foreground transition-colors hover:text-foreground"