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/package.json

@@ -0,0 +1,27 @@
+{
+  "name": "@sentryagent/portal",
+  "version": "1.0.0",
+  "private": true,
+  "scripts": {
+    "dev": "next dev",
+    "build": "next build",
+    "start": "next start",
+    "lint": "next lint"
+  },
+  "dependencies": {
+    "next": "14.2.5",
+    "react": "^18.3.1",
+    "react-dom": "^18.3.1",
+    "swagger-ui-react": "^5.17.14"
+  },
+  "devDependencies": {
+    "@types/node": "^20.14.0",
+    "@types/react": "^18.3.3",
+    "@types/react-dom": "^18.3.0",
+    "@types/swagger-ui-react": "^4.18.3",
+    "autoprefixer": "^10.4.20",
+    "postcss": "^8.4.47",
+    "tailwindcss": "^3.4.12",
+    "typescript": "^5.5.3"
+  }
+}