refactor: split monolith into 3 microservices (frontend, backend, discord-gateway)

- Extract services into services/{frontend,backend,discord-gateway}
- Create packages/shared/ for shared logger, errors, utils, types
- Setup Modular MVC pattern in backend (controller→service→repository)
- Setup event-driven architecture in discord-gateway with Redis pub/sub
- Move Docker files to infra/docker/ with per-service Dockerfiles
- Update docker-compose.yml to use Traefik-only routing (no port exposes)
- Update GitHub Actions deploy workflow for multi-service matrix build
- Fix all import paths and resolve type errors across all services
- All 3 services pass tsc --noEmit clean

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

services/backend/src/index.ts

@@ -0,0 +1,38 @@
+import { startHttpServer } from "./http/server.js";
+import { createChildLogger } from "./shared/logger/index.js";
+
+const logger = createChildLogger("backend");
+
+async function main() {
+  try {
+    logger.info("Starting Discord Moderation Backend Service");
+    await startHttpServer();
+    logger.info("Backend service ready");
+  } catch (err) {
+    logger.error({ err }, "Failed to start backend service");
+    process.exit(1);
+  }
+}
+
+// Graceful shutdown
+process.on("SIGINT", () => {
+  logger.info("Received SIGINT, shutting down gracefully");
+  process.exit(0);
+});
+
+process.on("SIGTERM", () => {
+  logger.info("Received SIGTERM, shutting down gracefully");
+  process.exit(0);
+});
+
+process.on("uncaughtException", (err) => {
+  logger.error({ err }, "Uncaught exception");
+  process.exit(1);
+});
+
+process.on("unhandledRejection", (reason) => {
+  logger.error({ reason }, "Unhandled rejection");
+  process.exit(1);
+});
+
+main();