refactor: atomic, DRY, and logging improvements across codebase

- Split llmModerationClient.ts (2170 lines) into 5 focused sub-modules
- Split aiAnalyzer.ts (1282 lines) into 4 modular pipelines
- Split messages.db.ts (826 lines) into 5 domain-specific modules
- Moved shared schema to @bete/shared, eliminated backend duplication
- Added createChildLogger to all voice-recording and AI moderation modules
- Extracted tryCommandThenFallback, normalizeMediaState, DEFAULT_VOICE_STATUS
- Created shared pagination.ts utility, eliminated 5+ cursor-pagination duplications
- Created shared messageMapper.ts for row mapping
- Standardized backend error handling with asyncHandler
- Added frontend createLogger utility and useAsyncAction hook
- Added structured logging to frontend hooks, socket, and API client

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

services/frontend/src/shared/lib/logger.ts

@@ -0,0 +1,22 @@
+// ─── Client-side structured logger ────────────────────────────────────────
+
+const LOG_PREFIX = "[Bete]";
+
+export function createLogger(context: string) {
+  const prefix = `${LOG_PREFIX} [${context}]`;
+
+  return {
+    debug: (msg: string, data?: Record<string, unknown>) => {
+      if (import.meta.env.DEV) console.debug(prefix, msg, data ?? "");
+    },
+    info: (msg: string, data?: Record<string, unknown>) => {
+      console.info(prefix, msg, data ?? "");
+    },
+    warn: (msg: string, data?: Record<string, unknown>) => {
+      console.warn(prefix, msg, data ?? "");
+    },
+    error: (msg: string, data?: Record<string, unknown>) => {
+      console.error(prefix, msg, data ?? "");
+    },
+  };
+}