feat: Complete NestJS backend scaffold — 22 modules, 39 entities, WebSocket gateway

Full backend rewrite from Rust/Axum to NestJS/TypeScript.
- 22 feature modules (auth, servers, wipes, maps, plugins, players, console,
  chat, team, notifications, settings, schedules, analytics, alerts, status,
  store, webstore, admin, setup, migration, users, licenses)
- 39 TypeORM entities matching PostgreSQL schema (12 migrations)
- Common infrastructure: JWT/RBAC guards, decorators, exception filter
- NATS service with pub/sub/request-reply
- Socket.IO WebSocket gateway with NATS bridge
- Docker: NestJS Dockerfile + updated docker-compose.yml
- Zero compile errors (npx tsc --noEmit clean)

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

docker/Dockerfile.api.nestjs

@@ -0,0 +1,37 @@
+# Multi-stage build for Corrosion NestJS API
+# Stage 1: Build
+FROM node:20-alpine AS builder
+
+WORKDIR /app
+
+# Copy package files
+COPY package*.json ./
+
+# Install dependencies
+RUN npm ci
+
+# Copy source
+COPY . .
+
+# Build TypeScript
+RUN npm run build
+
+# Stage 2: Production
+FROM node:20-alpine
+
+WORKDIR /app
+
+# Copy built output and production dependencies
+COPY --from=builder /app/dist ./dist
+COPY --from=builder /app/node_modules ./node_modules
+COPY --from=builder /app/package.json ./
+
+# Non-root user
+RUN addgroup -g 1001 -S nodejs && \
+    adduser -S nestjs -u 1001 && \
+    chown -R nestjs:nodejs /app
+USER nestjs
+
+EXPOSE 3000
+
+CMD ["node", "dist/main.js"]