Update footer copyright year to 2026

Bump the footer copyright in .vitepress/config.mts from 2025 to 2026 to reflect the new year.

Author: aaronparker

.vitepress/config.mts

@@ -110,7 +110,7 @@ export default defineConfig({
 
     footer: {
       message: 'A stealthpuppy project.',
-      copyright: 'Copyright © 2025 Aaron Parker.'
+      copyright: 'Copyright © 2026 Aaron Parker.'
     },
 
     editLink: {