feat(web): add saved searches, image lightbox, and web vitals tracking

New features:
- Saved searches dashboard page with CRUD hooks and API client
- Image lightbox component for property gallery full-screen viewing
- Web vitals provider and reporting utilities for performance monitoring
- Image blur placeholder generation utility

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/web/lib/image-blur.ts

@@ -0,0 +1,53 @@
+/**
+ * Tiny SVG-based blur placeholder for next/image.
+ *
+ * Generates a small, inline base64-encoded SVG that next/image displays while
+ * the real image loads. This eliminates layout shift (CLS) and provides a smooth
+ * visual transition without needing to pre-compute per-image blur hashes.
+ *
+ * Usage:
+ *   <Image placeholder="blur" blurDataURL={shimmerBlurDataURL()} ... />
+ */
+
+const SHIMMER_SVG = `
+<svg width="400" height="300" xmlns="http://www.w3.org/2000/svg">
+  <defs>
+    <linearGradient id="g" x1="0%" y1="0%" x2="100%" y2="0%">
+      <stop offset="0%" stop-color="#e5e7eb"/>
+      <stop offset="50%" stop-color="#f3f4f6"/>
+      <stop offset="100%" stop-color="#e5e7eb"/>
+    </linearGradient>
+  </defs>
+  <rect width="400" height="300" fill="#e5e7eb"/>
+  <rect width="400" height="300" fill="url(#g)">
+    <animate attributeName="x" from="-400" to="400" dur="1.5s" repeatCount="indefinite"/>
+  </rect>
+</svg>`.trim();
+
+const STATIC_BLUR_SVG = `
+<svg width="8" height="6" xmlns="http://www.w3.org/2000/svg">
+  <rect width="8" height="6" fill="#d1d5db"/>
+</svg>`.trim();
+
+function toBase64(str: string): string {
+  if (typeof window === 'undefined') {
+    return Buffer.from(str).toString('base64');
+  }
+  return btoa(str);
+}
+
+/**
+ * Animated shimmer blur placeholder (for listing thumbnails).
+ * Shows a shimmer animation while the image loads.
+ */
+export function shimmerBlurDataURL(): string {
+  return `data:image/svg+xml;base64,${toBase64(SHIMMER_SVG)}`;
+}
+
+/**
+ * Static grey blur placeholder (for small thumbnails like table rows).
+ * Lightweight, no animation.
+ */
+export function staticBlurDataURL(): string {
+  return `data:image/svg+xml;base64,${toBase64(STATIC_BLUR_SVG)}`;
+}