refactor: comprehensive codebase cleanup and architecture hardening

- Sprint 1 (Quick Wins): Remove dead analytics modules, fix 4 unresolved
  imports, replace 3 console.warn with logger, remove mock-crc import
- Sprint 2 (Architecture): Create MascotChatRepository, AnalysisRepository,
  3 Zod schemas (mascot-chat, analysis, voice), deduplicate error classes,
  move 3 SQL queries from routes to repository
- Sprint 3 (Complexity): Replace 7 any types with proper interfaces,
  extract 6 helpers from prepareMediaMessage (CC 85 -> ~15)
- Sprint 4 (Config): Remove 22 dead env vars from .env, add 30 missing
  vars to .env.example, standardize naming

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

services/backend/src/modules/mascot-chat/mascot-chat.controller.ts

@@ -1,5 +1,5 @@
-import type { Request, Response } from "express";
 import { createChildLogger } from "@bete/shared/logger";
+import type { Request, Response } from "express";
 import { mascotChatService } from "./mascot-chat.service.js";
 
 const logger = createChildLogger("mascot-chat.controller");
@@ -20,11 +20,15 @@ export async function handleMascotChat(req: Request, res: Response) {
 
     logger.debug(
       { userId, messageLength: message.length, context },
-      "Received mascot chat message"
+      "Received mascot chat message",
     );
 
     // Process message & generate response
-    const response = await mascotChatService.processMessage(message, context, userId);
+    const response = await mascotChatService.processMessage(
+      message,
+      context,
+      userId,
+    );
 
     // Save conversation to database
     await mascotChatService.saveConversation({