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/frontend/src/widgets/Header.tsx

@@ -10,13 +10,11 @@ import type { WsStatus } from "../shared/ws/socket";
 const titles: Record<DashboardTab, string> = {
   live: "Voice, Media & Recordings",
   messages: "Messages & Moderation",
-  analytics: "Analytics & Insights",
 };
 
 const subtitles: Record<DashboardTab, string> = {
   live: "Join voice channels, play media, stream audio, and browse recordings.",
   messages: "Capture, analyse, and moderate Discord messages.",
-  analytics: "Server moderation statistics and trends.",
 };
 
 interface HeaderProps {

services/frontend/src/widgets/Sidebar.tsx

@@ -1,5 +1,5 @@
 import { motion } from "framer-motion";
-import { BarChart3, MessageSquare, Radio } from "lucide-react";
+import { MessageSquare, Radio } from "lucide-react";
 import type { DashboardTab } from "../entities/ui/types";
 import type { MessageRecord } from "../shared/api/client";
 import { useMascotChat } from "../shared/hooks/useMascotChat";
@@ -11,7 +11,6 @@ const navItems: Array<{ id: DashboardTab; label: string; icon: typeof Radio }> =
   [
     { id: "live", label: "Live", icon: Radio },
     { id: "messages", label: "Messages", icon: MessageSquare },
-    { id: "analytics", label: "Analytics", icon: BarChart3 },
   ];
 
 interface SidebarProps {
@@ -37,7 +36,7 @@ export function Sidebar({
       recentMessages.map((message) => message.user_id),
     ).size,
     lastActivity: recentMessages.length > 0 ? "Active" : "Idle",
-    topicsDiscussed: ["Messages", "Moderation", "Analytics"],
+    topicsDiscussed: ["Messages", "Moderation"],
     guildId,
     channelId,
   });

services/frontend/src/widgets/mascot/MascotChatbot.tsx

@@ -32,7 +32,8 @@ export function MascotChatbot({
     {
       id: "init-1",
       role: "mascot",
-      content: "Halo! 👋 Saya mascot mu. Ada yang bisa aku bantu tentang conversation atau analytics?",
+      content:
+        "Halo! 👋 Saya mascot mu. Ada yang bisa aku bantu tentang conversation atau analytics?",
       timestamp: Date.now(),
     },
   ]);
@@ -162,7 +163,7 @@ export function MascotChatbot({
                   animate={{ opacity: 1, y: 0 }}
                   className={cn(
                     "flex gap-2",
-                    message.role === "user" ? "justify-end" : "justify-start"
+                    message.role === "user" ? "justify-end" : "justify-start",
                   )}
                 >
                   {message.role === "mascot" && (
@@ -177,7 +178,7 @@ export function MascotChatbot({
                       "max-w-xs px-3 py-2 rounded-xl text-sm break-words",
                       message.role === "user"
                         ? "bg-primary text-white rounded-br-none"
-                        : "bg-muted text-foreground rounded-bl-none"
+                        : "bg-muted text-foreground rounded-bl-none",
                     )}
                   >
                     {message.content}
@@ -204,12 +205,20 @@ export function MascotChatbot({
                       />
                       <motion.div
                         animate={{ y: [0, -4, 0] }}
-                        transition={{ duration: 0.6, repeat: Infinity, delay: 0.1 }}
+                        transition={{
+                          duration: 0.6,
+                          repeat: Infinity,
+                          delay: 0.1,
+                        }}
                         className="w-2 h-2 bg-muted-foreground rounded-full"
                       />
                       <motion.div
                         animate={{ y: [0, -4, 0] }}
-                        transition={{ duration: 0.6, repeat: Infinity, delay: 0.2 }}
+                        transition={{
+                          duration: 0.6,
+                          repeat: Infinity,
+                          delay: 0.2,
+                        }}
                         className="w-2 h-2 bg-muted-foreground rounded-full"
                       />
                     </div>
@@ -252,15 +261,20 @@ export function MascotChatbot({
 }
 
 // Default mascot responses based on keywords
-function generateMascotResponse(input: string, messages: ChatMessage[]): string {
+function generateMascotResponse(
+  input: string,
+  messages: ChatMessage[],
+): string {
   const lowerInput = input.toLowerCase();
   const responseMap: Record<string, string> = {
     halo: "Halo juga! 👋 Senang ketemu kamu. Ada yang bisa aku bantu?",
     terima: "Sama-sama! 😊",
     apa: "Aku adalah mascot virtual yang membantu kamu memahami conversation dan analytics. Tanya aku apa saja!",
-    siapa: "Aku mascot mu yang baik hati! Siap membantu dengan insights tentang chat dan analytics.",
+    siapa:
+      "Aku mascot mu yang baik hati! Siap membantu dengan insights tentang chat dan analytics.",
     chat: "Setiap chat yang terjadi di sini aku analisis untuk memberikan insights yang berguna. Keren kan? 😎",
-    pesan: "Aku bisa memberikan ringkasan tentang pesan-pesan yang dikirim, siapa yang paling aktif, dan topik populer!",
+    pesan:
+      "Aku bisa memberikan ringkasan tentang pesan-pesan yang dikirim, siapa yang paling aktif, dan topik populer!",
     analitik:
       "Analytics menunjukkan pola conversation, waktu aktif, partisipan utama, dan banyak hal menarik lainnya! 📊",
     berapa:

services/frontend/src/widgets/mascot/MascotImage.tsx

@@ -1,6 +1,6 @@
 import { motion } from "framer-motion";
 import { MessageCircle } from "lucide-react";
-import { useState, useEffect } from "react";
+import { useEffect, useState } from "react";
 
 /**
  * MascotImage — Anime mascot PNG from GitHub CDN