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/http/app.ts

@@ -1,3 +1,4 @@
+import { createChildLogger } from "@bete/shared/logger";
 import express, {
   type Express,
   type NextFunction,
@@ -6,7 +7,6 @@ import express, {
 } from "express";
 import helmet from "helmet";
 import { createAnalysisRouter } from "../modules/analysis/analysis.routes.js";
-import { createAnalyticsRouter } from "../modules/analytics/analytics.routes.js";
 import { createAuthRouter } from "../modules/auth/auth.routes.js";
 import { createConfigRouter } from "../modules/config/config.routes.js";
 import { createHealthRouter } from "../modules/health/health.routes.js";
@@ -15,9 +15,8 @@ import { createMediaRouter } from "../modules/media/media.routes.js";
 import { createMessagesRouter } from "../modules/messages/messages.routes.js";
 import { createRecordingsRouter } from "../modules/recordings/recordings.routes.js";
 import { createUiStateRouter } from "../modules/ui-state/ui-state.routes.js";
-import { createVoiceRouter } from "../modules/voice/voice.routes.js";
 import { createGuildsRouter } from "../modules/voice/guilds.routes.js";
-import { createChildLogger } from "@bete/shared/logger";
+import { createVoiceRouter } from "../modules/voice/voice.routes.js";
 import { errorHandler } from "../shared/middlewares/index.js";
 
 const logger = createChildLogger("http.app");
@@ -66,7 +65,6 @@ export function createHttpApp(): Express {
   app.use("/api", createConfigRouter());
   app.use("/api", createMessagesRouter());
   app.use("/api", createAnalysisRouter());
-  app.use("/api", createAnalyticsRouter());
   app.use("/api", createMascotChatRouter());
   app.use("/api", createMediaRouter());
   app.use("/api", createVoiceRouter());

services/backend/src/http/server.ts

@@ -1,10 +1,10 @@
 import { createServer, type Server } from "node:http";
+import { createChildLogger } from "@bete/shared/logger";
 import { config } from "../shared/config/index.js";
 import { initializeDatabase } from "../shared/database/index.js";
-import { createChildLogger } from "@bete/shared/logger";
-import { createHttpApp } from "./app.js";
-import { createWebSocketServer } from "../ws/server.js";
 import { startRedisBridge } from "../ws/redis-bridge.js";
+import { createWebSocketServer } from "../ws/server.js";
+import { createHttpApp } from "./app.js";
 
 const logger = createChildLogger("http.server");