refactor: large codebase cleanup - consolidate schemas, migrate to Drizzle ORM, extract frontend components, modernize Docker builds

- Consolidate all DB schema definitions into packages/shared as single source of truth
- Migrate backend from raw SQL to Drizzle ORM across all modules
- Extract frontend inline UI into separate component files
- Refactor discord-gateway circuitBreaker into conversationState + moderationState
- Convert messageStore to Proxy singleton pattern
- Add validateBody/validateQuery middleware + Zod schemas for API endpoints
- Modernize Docker builds with multi-stage + pnpm deploy
- Migrate CI/CD from deployment to image-based pipeline
- Remove 60+ unused/dead files (~15K lines)
- Update color scheme from sky-blue to teal-cyan
- Move DB connection management to @bete/shared/database

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

services/backend/src/modules/media/media.schema.ts

@@ -0,0 +1,13 @@
+import { z } from "zod";
+
+export const mediaQueueSchema = z.object({
+  source: z.string().min(1, "source is required"),
+  mode: z.enum(["music", "screen"]).default("music"),
+});
+
+export const mediaVolumeSchema = z.object({
+  volume: z.number().min(0).max(1).default(1.0),
+});
+
+export type MediaQueueInput = z.infer<typeof mediaQueueSchema>;
+export type MediaVolumeInput = z.infer<typeof mediaVolumeSchema>;