feat(phase-4): WS2 + WS3 — Developer Portal (Next.js 14) and CLI tool (sentryagent)

WS2: Developer Portal (portal/)
- Standalone Next.js 14 + Tailwind CSS app — independent deployment
- Home page: hero, feature grid, CTA to /get-started
- /pricing: free tier limits table (10 agents, 1k calls/day) + paid tier CTA
- /sdks: all 4 SDKs (Node.js, Python, Go, Java) with install + code examples
- /api-explorer: Swagger UI from NEXT_PUBLIC_API_URL/openapi.json, persistAuthorization
- /get-started: 4-step wizard (setup → register agent → credentials → SDK snippet)
- Shared Nav component with active-link highlighting
- Build: 8/8 static pages, zero TypeScript errors

WS3: CLI Tool (cli/ — npm package: sentryagent)
- configure, register-agent, list-agents, issue-token, rotate-credentials, tail-audit-log
- Auto OAuth2 token fetch + 30s-buffer cache via client_credentials flow
- chalk-formatted table output, confirmation prompts, bounded audit log dedup
- bash + zsh shell completion scripts
- README with installation, all commands, and completion setup
- Build: tsc clean, node dist/index.js --help verified

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

portal/components/Nav.tsx

@@ -0,0 +1,66 @@
+'use client';
+
+import React from 'react';
+import Link from 'next/link';
+import { usePathname } from 'next/navigation';
+
+interface NavLink {
+  href: string;
+  label: string;
+}
+
+const links: NavLink[] = [
+  { href: '/', label: 'Home' },
+  { href: '/api-explorer', label: 'API Explorer' },
+  { href: '/get-started', label: 'Get Started' },
+  { href: '/sdks', label: 'SDKs' },
+  { href: '/pricing', label: 'Pricing' },
+];
+
+export function Nav(): React.ReactElement {
+  const pathname = usePathname();
+
+  return (
+    <header className="sticky top-0 z-50 border-b border-slate-200 bg-white/90 backdrop-blur">
+      <nav className="mx-auto flex max-w-7xl items-center justify-between px-6 py-4">
+        <Link href="/" className="flex items-center gap-2">
+          <span className="text-xl font-bold text-brand-600">
+            SentryAgent
+          </span>
+          <span className="rounded bg-brand-100 px-1.5 py-0.5 text-xs font-semibold text-brand-700">
+            AgentIdP
+          </span>
+        </Link>
+
+        <ul className="flex items-center gap-1">
+          {links.map(({ href, label }) => {
+            const isActive =
+              href === '/' ? pathname === '/' : pathname.startsWith(href);
+            return (
+              <li key={href}>
+                <Link
+                  href={href}
+                  className={[
+                    'rounded-md px-3 py-2 text-sm font-medium transition-colors',
+                    isActive
+                      ? 'bg-brand-100 text-brand-700'
+                      : 'text-slate-600 hover:bg-slate-100 hover:text-slate-900',
+                  ].join(' ')}
+                >
+                  {label}
+                </Link>
+              </li>
+            );
+          })}
+        </ul>
+
+        <Link
+          href="/get-started"
+          className="rounded-lg bg-brand-600 px-4 py-2 text-sm font-semibold text-white shadow-sm transition-colors hover:bg-brand-700"
+        >
+          Get Started Free
+        </Link>
+      </nav>
+    </header>
+  );
+}