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/discord-gateway/src/shared/discord/clientOptions.ts

@@ -0,0 +1,21 @@
+import { type ClientOptions, Options } from "discord.js-selfbot-v13";
+
+export function createDiscordClientOptions(): ClientOptions {
+  return {
+    makeCache: Options.cacheWithLimits({
+      ...Options.defaultMakeCacheSettings,
+      MessageManager: 25,
+      ReactionManager: 0,
+      ReactionUserManager: 0,
+      PresenceManager: 0,
+    }),
+    partials: ["USER", "CHANNEL", "GUILD_MEMBER", "MESSAGE"],
+    sweepers: {
+      messages: { interval: 300, lifetime: 600 },
+      threads: { interval: 3600, lifetime: 14400 },
+    },
+    restRequestTimeout: 15_000,
+    retryLimit: 2,
+    restGlobalRateLimit: 45,
+  };
+}