refactor: break monorepo into 3 standalone services (gateway, backend, frontend)

- Remove pnpm workspace, moon repo, and all monorepo tooling
- Delete packages/shared/, embed shared code directly into each service
- Copy packages/shared/src/* -> services/backend/src/shared/ and services/discord-gateway/src/shared/
- Replace all @bete/shared imports with @/shared/ path alias
- Remove @bete/shared workspace dependency from both services
- Update root package.json scripts from --filter to --prefix
- Rewrite Dockerfiles to build each service standalone
- Clean up biome.json, .gitignore, remove root drizzle.config.ts

services/discord-gateway/src/modules/event-broadcaster/eventBroadcaster.ts

@@ -1,5 +1,5 @@
-import type { AttachmentRecord, MessageRecord } from "@bete/shared";
-import { type CustomLogger, createChildLogger } from "@bete/shared/logger";
+import type { AttachmentRecord, MessageRecord } from "../../shared/index.js";
+import { type CustomLogger, createChildLogger } from "../../shared/logger/index.js";
 import Redis from "ioredis";
 import { type DiscordGatewayEvent, EventChannels } from "./eventTypes.js";
 

services/discord-gateway/src/modules/event-broadcaster/eventTypes.ts

@@ -22,7 +22,7 @@ import {
   DISCORD_VOICE_STOPPED,
   DISCORD_VOICE_UPLOADED,
   type DiscordGatewayEvent,
-} from "@bete/shared";
+} from "../../shared/index.js";
 
 export type { DiscordGatewayEvent };