Improve footer and version history display

- Add build timestamp to footer
- Rename GitHub links for clarity (Source Code, Firmware Indexer, Raw Data)
- Remove height limit from version history sidebar

next.config.ts

@@ -6,6 +6,9 @@ const nextConfig: NextConfig = {
   output: "export",
   basePath,
   assetPrefix: basePath || undefined,
+  env: {
+    NEXT_PUBLIC_BUILD_TIME: new Date().toISOString(),
+  },
 };
 
 export default nextConfig;