Add logo, animated explainer, trust section and photo-privacy guides

Reposition around EXIF/GPS/C2PA privacy, replace dead HowTo/FAQ schema,
add three guide pages with sitemap and internal links.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

public/manifest.json

@@ -1,8 +1,8 @@
 {
   "id": "/",
-  "name": "Untrace — content credentials and metadata remover",
+  "name": "Untrace — photo metadata and content credentials remover",
   "short_name": "Untrace",
-  "description": "Remove C2PA content credentials, AI generation tags and EXIF metadata from images, entirely in your browser.",
+  "description": "See and remove EXIF, GPS and C2PA metadata from photos, entirely in your browser.",
   "start_url": "/",
   "scope": "/",
   "display": "standalone",
@@ -20,10 +20,26 @@
       "sizes": "any",
       "type": "image/svg+xml",
       "purpose": "maskable"
+    },
+    {
+      "src": "/icon-192.png",
+      "sizes": "192x192",
+      "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/logo-512.png",
+      "sizes": "512x512",
+      "type": "image/png",
+      "purpose": "any"
     }
   ],
-  "categories": ["productivity", "utilities", "photo"],
+  "categories": [
+    "productivity",
+    "utilities",
+    "photo"
+  ],
   "lang": "en",
   "dir": "ltr",
   "orientation": "any"
-}
+}