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/discord-gateway/src/modules/ai-moderation/searxngSearch.ts

@@ -18,6 +18,11 @@ let redis: Redis | null = null;
  */
 export function initSearxngCache(redisUrl: string): void {
   if (redis) return;
+  // Dedicated Redis connection needed because: this connection serves as an
+  // optional cache for SearXNG web search results with graceful degradation
+  // when Redis is unavailable (lazyConnect + null-assignment on failure).
+  // It uses custom retry strategy and must not block or break the main event
+  // pipeline if the cache is down.
   redis = new Redis(redisUrl, {
     maxRetriesPerRequest: 3,
     retryStrategy(times) {