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/http/app.ts

@@ -0,0 +1,75 @@
+import express, {
+  type Express,
+  type NextFunction,
+  type Request,
+  type Response,
+} from "express";
+import helmet from "helmet";
+import { createAnalyticsRouter } from "../modules/analytics/routes/index.js";
+import { createHealthRouter } from "../modules/health/routes/index.js";
+import { createMediaRouter } from "../modules/media/routes/index.js";
+import { createMessagesRouter } from "../modules/messages/routes/index.js";
+import { createVoiceRouter } from "../modules/voice/routes/index.js";
+import { createChildLogger } from "../shared/logger/index.js";
+import { errorHandler } from "../shared/middlewares/index.js";
+
+const logger = createChildLogger("http.app");
+
+export function createHttpApp(): Express {
+  const app = express();
+
+  // Security middleware
+  app.use(
+    helmet({
+      contentSecurityPolicy: false,
+    }),
+  );
+
+  // Body parsing
+  app.use(express.json());
+  app.use(express.urlencoded({ extended: true }));
+
+  // Request logging
+  app.use((req: Request, res: Response, next: NextFunction) => {
+    if (req.path.startsWith("/api/")) {
+      res.set("Cache-Control", "no-store");
+    }
+    res.on("finish", () => {
+      if (req.originalUrl.startsWith("/.well-known/")) return;
+      if (req.originalUrl === "/favicon.ico") return;
+      if (res.statusCode >= 400) {
+        logger.warn(
+          {
+            method: req.method,
+            url: req.originalUrl,
+            statusCode: res.statusCode,
+          },
+          "HTTP request failed",
+        );
+      }
+    });
+    next();
+  });
+
+  // Health check (no auth required)
+  app.use("/api", createHealthRouter());
+
+  // API routes
+  app.use("/api", createMessagesRouter());
+  app.use("/api", createAnalyticsRouter());
+  app.use("/api", createMediaRouter());
+  app.use("/api", createVoiceRouter());
+
+  // 404 handler
+  app.use((_req: Request, res: Response) => {
+    res.status(404).json({
+      error: "NOT_FOUND",
+      message: "Endpoint not found",
+    });
+  });
+
+  // Error handler (must be last)
+  app.use(errorHandler);
+
+  return app;
+}

services/backend/src/http/server.ts

@@ -0,0 +1,25 @@
+import { config } from "../shared/config/index.js";
+import { initializeDatabase } from "../shared/database/index.js";
+import { createChildLogger } from "../shared/logger/index.js";
+import { createHttpApp } from "./app.js";
+
+const logger = createChildLogger("http.server");
+
+export async function startHttpServer() {
+  await initializeDatabase();
+
+  const app = createHttpApp();
+  const port = config.WEBSERVER_PORT;
+
+  return new Promise<void>((resolve, reject) => {
+    const server = app.listen(port, () => {
+      logger.info({ port }, "HTTP server started");
+      resolve();
+    });
+
+    server.on("error", (err) => {
+      logger.error({ err }, "HTTP server error");
+      reject(err);
+    });
+  });
+}