feat(web): import oh-my-openagent-web Next.js + Cloudflare Workers site

Imports the public marketing site previously living in
../oh-my-opencode-web. Independent of the npm plugin: own package.json,
bun.lock, tsconfig.json. Not included in the published package — root
files: array still only ships dist/, bin/, postinstall.mjs.

Stack:
- Next.js 15.5 App Router + RSC, deployed to Cloudflare Workers via
  @opennextjs/cloudflare (build target .open-next/worker.js).
- Tailwind v4 + shadcn/ui primitives.
- next-intl with 4 locales (en/ja/ko/zh) under app/[locale]/.
- Playwright e2e tests under web/e2e/.
- Custom domains ohmyopenagent.com (primary) and ohmyopencode.org
  (legacy alias) declared in web/wrangler.toml.

Source files were re-formatted via `bun run format` to bring them in
line with the existing .prettierrc (singleQuote: false). Functional code
unchanged.

web/components/landing/install-command.tsx

@@ -0,0 +1,39 @@
+"use client"
+
+import { useState } from "react"
+import { Copy, Check } from "lucide-react"
+import { Button } from "@/components/ui/button"
+
+export function InstallCommand({ command }: { command: string }) {
+  const [copied, setCopied] = useState(false)
+
+  const copyCommand = async () => {
+    try {
+      await navigator.clipboard.writeText(command)
+      setCopied(true)
+      window.setTimeout(() => setCopied(false), 2000)
+    } catch (err) {
+      console.warn("Failed to copy install command", err)
+    }
+  }
+
+  return (
+    <div className="relative rounded-lg border border-zinc-800 bg-black/50 p-4 font-mono text-sm text-zinc-300 shadow-2xl shadow-cyan-500/10 backdrop-blur-sm">
+      <div className="flex items-center justify-between">
+        <div className="flex items-center gap-2">
+          <span className="text-cyan-500">$</span>
+          <span>{command}</span>
+        </div>
+        <Button
+          variant="ghost"
+          size="icon"
+          className="h-8 w-8 text-zinc-400 hover:text-white"
+          onClick={copyCommand}
+          aria-label="Copy install command"
+        >
+          {copied ? <Check className="h-4 w-4 text-green-500" /> : <Copy className="h-4 w-4" />}
+        </Button>
+      </div>
+    </div>
+  )
+}