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/shared/logger/index.ts

@@ -0,0 +1,24 @@
+import pino from "pino";
+import { config } from "../config/index.js";
+
+const isDev = config.NODE_ENV === "development";
+
+export const logger = pino({
+  level: config.LOG_LEVEL,
+  transport: isDev
+    ? {
+        target: "pino-pretty",
+        options: {
+          colorize: true,
+          translateTime: "SYS:standard",
+          ignore: "pid,hostname",
+        },
+      }
+    : undefined,
+});
+
+export function createChildLogger(context: string) {
+  return logger.child({ context });
+}
+
+export type Logger = ReturnType<typeof createChildLogger>;