Add PhotoSwipe dependency and fix PhotoGallery error handling

- Install photoswipe@^5.4.4 (missing in previous commit)
- Fix TypeScript error: properly handle unknown error type in catch block

Author: saadshahd

bun.lock

@@ -7,10 +7,12 @@
     "@tailwindcss/vite": "^4.1.16",
     "@types/bun": "latest",
     "@types/headroom": "^0.12.4",
+    "@types/sharp": "^0.32.0",
     "astro": "^5.15.1",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "playwright": "^1.56.1",
+    "sharp": "^0.34.4",
     "tailwindcss": "^4.1.16",
     "typescript": "^5"
   },
@@ -31,6 +33,8 @@
     "astro-mermaid": "^1.1.0",
     "headroom.js": "^0.12.0",
     "motion": "^12.23.24",
-    "shiki": "^3.13.0"
+    "photoswipe": "^5.4.4",
+    "shiki": "^3.13.0",
+    "zod": "^4.1.12"
   }
 }

package.json

@@ -54,8 +54,9 @@ let photos;
 try {
   photos = validatePhotos(rawPhotos);
 } catch (error) {
+  const message = error instanceof Error ? error.message : String(error);
   throw new Error(
-    `PhotoGallery: Invalid photo data\n${error.message}\n` +
+    `PhotoGallery: Invalid photo data\n${message}\n` +
       `Check your JSON file for schema violations (src, alt, caption, width, height)`,
   );
 }