feat: photography features & image optimizations

- Hero carousel: gallery.yaml hero accepts single UUID or array, crossfade component
- Full-bleed single albums: subpages with 1 album skip grid, render photos directly
- EXIF on hover: camera/lens/focal length overlay on grid items (toggle via exifOnHover)
- Customizable grid: columns/gap/aspectRatio/layout (masonry|uniform) via gallery.yaml
- Per-subpage grid overrides: each subpage can override global grid config
- True masonry: per-image aspect ratios from EXIF dimensions
- next/image migration: homepage hero, album covers, grid thumbnails, about portrait
- ThumbHash blur placeholders and dominant color backgrounds
- Custom next/image loader via image proxy with width/quality params
- Lightbox fade-in transition with dominant color background
- Password-protected subpages, health check, rate limiting, OG images

next.config.ts

@@ -2,6 +2,10 @@ import type { NextConfig } from "next";
 
 const nextConfig: NextConfig = {
   output: 'standalone',
+  images: {
+    loader: 'custom',
+    loaderFile: './lib/immichLoader.ts',
+  },
 };
 
 export default nextConfig;