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

@@ -1,7 +1,10 @@
+import { createChildLogger } from "@bete/shared/logger";
 import { encoding_for_model as encodingForModel } from "tiktoken";
 import { formatMediaEvidenceForPrompt } from "../message-capture/messageMetadata.js";
 import type { MessageRecord } from "../message-capture/types.js";
 
+const logger = createChildLogger("conversationContext");
+
 export interface ConversationContextInput {
   contextBefore: MessageRecord[];
   targets: MessageRecord[];
@@ -29,7 +32,12 @@ function formatTimestamp(ms: number): string {
  */
 export function estimateTokens(text: string): number {
   // Use tiktoken for accurate token counting (+15 overhead for JSON structure)
-  return getEncoder().encode(text).length + 15;
+  const tokens = getEncoder().encode(text).length + 15;
+  logger.debug(
+    { tokenEstimate: tokens, textLength: text.length },
+    "Estimated tokens for text",
+  );
+  return tokens;
 }
 
 /**
@@ -81,5 +89,14 @@ export function buildConversationContext(
     }
   }
 
+  logger.debug(
+    {
+      targetCount: targets.length,
+      contextCount: selectedContextLines.length,
+      usedTokens,
+      maxTokens,
+    },
+    "Conversation context built",
+  );
   return selectedContextLines;
 }