Add new styles and assets for the 2026 anniversary celebration

- Created mobile-specific CSS styles for the anniversary event.
- Added multiple PNG images for the gallery section of the 2026 anniversary.
- Implemented new Vue components for the Anniversary2026View, LetterView2026, and GalleryView2026.
- Updated navigation links in the CelebrationView to point to the 2025 anniversary.
- Enhanced layout and styling for the letter and gallery views to improve user experience.

Author: KYLN24

.vitepress/theme/index.ts

@@ -18,6 +18,15 @@ let customRoutes = [{
 }, {
     "path": "/about",
     "redirect": "/"
+}, {
+    "path": "/celebration",
+    "redirect": "/anniversary/2025"
+}, {
+    "path": "/celebration/gallery",
+    "redirect": "/anniversary/2025/gallery"
+}, {
+    "path": "/celebration/hole",
+    "redirect": "/anniversary/2025/hole"
 }]
 
 export default {