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/features/messages/components/MessageCard.tsx

@@ -225,7 +225,9 @@ function MessageRow({
       {shouldShowContent ? (
         <p
           className={`whitespace-pre-wrap break-words text-sm leading-6 ${
-            message.deleted_at ? "text-muted-foreground/60" : "text-foreground/90"
+            message.deleted_at
+              ? "text-muted-foreground/60"
+              : "text-foreground/90"
           }`}
         >
           {renderContentWithCustomEmojis(displayContent)}
@@ -412,7 +414,9 @@ export function MessageCard({ messages, onReanalyze }: MessageCardProps) {
 
           {/* Message rows — divided by separator when multiple */}
           <div
-            className={hasMultiple ? "divide-y divide-border/30 space-y-2.5" : ""}
+            className={
+              hasMultiple ? "divide-y divide-border/30 space-y-2.5" : ""
+            }
           >
             {messages.map((msg, idx) => (
               <div

services/frontend/src/features/messages/components/MessageFeed.tsx

@@ -2,7 +2,7 @@ import { motion } from "framer-motion";
 import { useEffect, useMemo, useRef } from "react";
 import type { MessageRecord } from "../../../shared/api/client";
 import { cardItem, cardStagger } from "../../../shared/hooks/useFramerStagger";
-import { ScrollArea, EmptyStateMascot } from "../../../shared/ui";
+import { EmptyStateMascot, ScrollArea } from "../../../shared/ui";
 import { MessageCard, MessageCardSkeleton } from "./MessageCard";
 
 export interface MessageFeedProps {
@@ -96,10 +96,7 @@ export function MessageFeed({
       >
         {groupedMessages.map((group) => (
           <motion.div key={group.messages[0].id} variants={cardItem}>
-            <MessageCard
-              messages={group.messages}
-              onReanalyze={onReanalyze}
-            />
+            <MessageCard messages={group.messages} onReanalyze={onReanalyze} />
           </motion.div>
         ))}