feat: initial full-stack nyaa-crawler implementation

- Node.js + TypeScript + Express backend using built-in node:sqlite
- React + Vite frontend with dark-themed UI
- Nyaa.si RSS polling via fast-xml-parser
- Watch list with show/episode CRUD and status tracking
- Auto-download scheduler with node-cron (configurable interval)
- .torrent file downloader with batch-release filtering
- Settings page for poll interval and quality defaults
- Dockerfile and docker-compose for Unraid deployment
- SQLite DB with migrations (shows, episodes, settings tables)

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

Dockerfile

@@ -0,0 +1,35 @@
+# ---- Build stage ----
+FROM node:20-alpine AS builder
+
+WORKDIR /app
+
+COPY package*.json ./
+RUN npm ci
+
+COPY . .
+RUN npm run build
+
+# ---- Production stage ----
+FROM node:20-alpine AS runner
+
+WORKDIR /app
+
+ENV NODE_ENV=production
+
+COPY package*.json ./
+RUN npm ci --omit=dev
+
+# Copy compiled server
+COPY --from=builder /app/dist ./dist
+
+# Default data directories
+RUN mkdir -p /data/torrents
+
+ENV PORT=3000
+ENV DATABASE_PATH=/data/db.sqlite
+ENV TORRENT_OUTPUT_DIR=/data/torrents
+ENV POLL_INTERVAL_SECONDS=900
+
+EXPOSE 3000
+
+CMD ["node", "dist/server/index.js"]