Add docs, blog, community pages and polish landing page layout

- Add docs pages (getting-started, changelog, keyboard-shortcuts)
- Add blog, community, and legal pages (privacy, terms, EULA)
- Add site header, footer, download button, and nav components
- Add sitemap and robots.txt generation
- Narrow main page container (max-w-2xl), fix footer positioning
- Switch README feature list to colon style

web/app/components/code-block.tsx

@@ -0,0 +1,59 @@
+import { codeToHtml } from "shiki";
+
+export async function CodeBlock({
+  children,
+  title,
+  lang,
+  variant = "code",
+}: {
+  children: string;
+  title?: string;
+  lang?: string;
+  variant?: "code" | "ascii";
+}) {
+  const lineHeightClass =
+    variant === "ascii" ? "leading-[1.15]" : "leading-[1.45]";
+
+  if (lang && variant !== "ascii") {
+    const html = await codeToHtml(children, {
+      lang,
+      themes: { light: "github-light", dark: "github-dark" },
+      defaultColor: false,
+    });
+
+    return (
+      <div className="mb-4">
+        {title && (
+          <div className="text-[11px] font-mono text-muted px-4 py-1.5 bg-code-bg border border-border border-b-0 rounded-t-lg">
+            {title}
+          </div>
+        )}
+        <div
+          className={`[&_pre]:bg-code-bg [&_pre]:border [&_pre]:border-border [&_pre]:px-4 [&_pre]:py-3 [&_pre]:overflow-x-auto [&_pre]:text-[13px] [&_pre]:${lineHeightClass} [&_pre]:font-mono ${
+            title
+              ? "[&_pre]:rounded-b-lg [&_pre]:border-t-0"
+              : "[&_pre]:rounded-lg"
+          } [&_code]:bg-transparent [&_code]:p-0`}
+          dangerouslySetInnerHTML={{ __html: html }}
+        />
+      </div>
+    );
+  }
+
+  return (
+    <div className="mb-4">
+      {title && (
+        <div className="text-[11px] font-mono text-muted px-4 py-1.5 bg-code-bg border border-border border-b-0 rounded-t-lg">
+          {title}
+        </div>
+      )}
+      <pre
+        className={`bg-code-bg border border-border px-4 py-3 overflow-x-auto text-[13px] ${lineHeightClass} font-mono ${
+          title ? "rounded-b-lg" : "rounded-lg"
+        }`}
+      >
+        <code>{children}</code>
+      </pre>
+    </div>
+  );
+}