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/modules/messages/messages.schema.ts

@@ -0,0 +1,35 @@
+import { z } from "zod";
+
+export const messageQuerySchema = z.object({
+  channelId: z.string().optional(),
+  guildId: z.string().optional(),
+  userId: z.string().optional(),
+  status: z.enum(["pending", "clean", "warn", "flagged", "error"]).optional(),
+  limit: z.coerce.number().int().positive().default(50),
+  offset: z.coerce.number().int().nonnegative().default(0),
+  cursor: z.string().optional(),
+});
+
+export const messageCreateSchema = z.object({
+  guildId: z.string(),
+  channelId: z.string(),
+  threadId: z.string().optional(),
+  userId: z.string(),
+  username: z.string(),
+  avatarUrl: z.string().optional(),
+  content: z.string(),
+  type: z.enum(["text", "edited", "deleted"]).default("text"),
+});
+
+export const messageUpdateSchema = z.object({
+  editedContent: z.string().optional(),
+  aiStatus: z.enum(["pending", "clean", "warn", "flagged", "error"]).optional(),
+  aiAnalysis: z.string().optional(),
+  aiCategories: z.string().optional(),
+  aiSeverity: z.enum(["none", "low", "medium", "high", "critical"]).optional(),
+  aiConfidence: z.number().optional(),
+});
+
+export type MessageQuery = z.infer<typeof messageQuerySchema>;
+export type MessageCreate = z.infer<typeof messageCreateSchema>;
+export type MessageUpdate = z.infer<typeof messageUpdateSchema>;