feat(brand): V-viewfinder 3a — the approved rebrand (was: split-W)

The V-viewfinder was approved during the favicon-v2 picker at
/v2/, then deployed prematurely (e7b9756) and reverted (81effca) after
the 'design pick is not a deploy command' lesson. Deploying it now with
explicit go-ahead.

Files: yellow V outline with the Camogli harbor visible inside, navy
field outside. Replaces the split-W (two Vs forming a W) across:
- favicon-16/32/64
- apple-touch-icon (180)
- icon-192 + icon-512 manifest icons
- icon-512-maskable (V at 65% safe zone)
- favicon.svg vector
- favicon.ico multi-res
- root-level apple-touch-icon{,-precomposed}.png for iOS fallback paths

Cache-bust query bumped to ?v=20260515-vviewfinder so browsers refetch.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

public/build/index.html

@@ -5,11 +5,11 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0, viewport-fit=cover" />
     <title>WeVisto</title>
 
-    <link rel="icon" type="image/svg+xml" href="/build/favicon.svg?v=20260515-3a" />
-    <link rel="icon" type="image/png" sizes="32x32" href="/build/icons/favicon-32.png?v=20260515-3a" />
-    <link rel="icon" type="image/png" sizes="16x16" href="/build/icons/favicon-16.png?v=20260515-3a" />
+    <link rel="icon" type="image/svg+xml" href="/build/favicon.svg?v=20260515-vviewfinder" />
+    <link rel="icon" type="image/png" sizes="32x32" href="/build/icons/favicon-32.png?v=20260515-vviewfinder" />
+    <link rel="icon" type="image/png" sizes="16x16" href="/build/icons/favicon-16.png?v=20260515-vviewfinder" />
     <link rel="manifest" href="/build/manifest.webmanifest" />
-    <link rel="apple-touch-icon" sizes="180x180" href="/build/icons/apple-touch-icon.png?v=20260515-3a" />
+    <link rel="apple-touch-icon" sizes="180x180" href="/build/icons/apple-touch-icon.png?v=20260515-vviewfinder" />
 
     <meta name="theme-color" content="#fdf6ee" />
     <meta name="apple-mobile-web-app-capable" content="yes" />