Add favicon, app icons, and OG thumbnail

Generated from logo with transparent background removal.
Favicon.ico, apple-touch-icon, icon PNGs (16-512px), and
1200x630 Open Graph image with grid pattern and branding.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

site/app/layout.tsx

@@ -17,17 +17,34 @@ export const metadata: Metadata = {
   title: "cladm — TUI launcher for Claude Code",
   description:
     "Browse all your projects, see git status at a glance, expand into sessions and branches, then launch everything in parallel Terminal windows.",
+  icons: {
+    icon: [
+      { url: "/favicon.ico", sizes: "32x32" },
+      { url: "/icon-192.png", sizes: "192x192", type: "image/png" },
+      { url: "/icon-512.png", sizes: "512x512", type: "image/png" },
+    ],
+    apple: "/apple-touch-icon.png",
+  },
   openGraph: {
     title: "cladm",
     description: "TUI launcher for Claude Code sessions",
     url: "https://claudm.com",
     siteName: "cladm",
     type: "website",
+    images: [
+      {
+        url: "/og-image.png",
+        width: 1200,
+        height: 630,
+        alt: "cladm — TUI launcher for Claude Code sessions",
+      },
+    ],
   },
   twitter: {
     card: "summary_large_image",
     title: "cladm",
     description: "TUI launcher for Claude Code sessions",
+    images: ["/og-image.png"],
   },
 };