Add crawler implementation (Node.js + TypeScript)

- Create crawler project structure
- Implement base crawler class with safety features
- Add crawlers for Ruliweb, Arcalive, DCInside
- Implement utilities: fetcher (with retry logic), logger
- Configure crawling settings (3s delay, max 20 posts/board)
- Add test script and scheduler (30min intervals)

Safety measures:
- 3 second delay between requests
- Exponential backoff retry logic
- Respect robots.txt (DCInside disabled)
- User-Agent and proper headers

Current status:
- Structure complete
- Both Ruliweb and Arcalive return 403 (bot detection)
- Need to decide: Puppeteer, switch targets, or use mock data

crawler/tsconfig.json

@@ -0,0 +1,16 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "node",
+    "esModuleInterop": true,
+    "strict": true,
+    "skipLibCheck": true,
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "resolveJsonModule": true,
+    "declaration": true
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist"]
+}