chore: clean up dead barrels, duplicate config, and orphaned frontend components

Gateway:
- Remove dead barrels (ai-moderation/index, attachment-upload/index, message-capture/index) — all consumers import files directly
- Remove orphaned schema/ split dir (analytics/cache/messages/meta) — schema.ts is monolithic
- Merge duplicate config singleton: delete shared/config/config.ts, point all 44 imports at shared/config/index

Backend:
- Remove dead commandHelper.ts (voice-era fallback), ws/index.ts barrel, health.schema.ts, moderationMetrics.ts, analysis.schema.ts (0 importers; metrics/handlers route directly)

Frontend:
- Remove orphaned CategoryDrilldown/CoverageTiles/TopicTrends, primitives/slot, use-mobile, use-mounted
- Remove unused charts donut/sparkline (TopicTrends was only consumer)

Kept (verified active): shared/database/index.ts facade (11 importers), hooks/index + lib/api/index barrels (10 importers), orpc/ws.ts, charts/index.ts barrel.
Verified: tsc + biome + vitest per service (backend e2e 3 failures pre-existing on main); frontend next build 8 routes.

services/discord-gateway/src/modules/message-capture/archiveEmbedder.ts

@@ -8,7 +8,7 @@ import {
   upsertQdrantPointV2,
 } from "@/modules/ai-moderation/qdrantClient";
 import { createChildLogger } from "@/shared/logger/index";
-import { config } from "../../shared/config/config.js";
+import { config } from "../../shared/config/index.js";
 
 const log = createChildLogger("archive-embedder");
 

services/discord-gateway/src/modules/message-capture/index.ts

@@ -1,19 +0,0 @@
-export {
-  getDisplayContent,
-  getMessageLocation,
-  getMessageMetadata,
-} from "../message-capture/messageMetadata.js";
-export type {
-  AIRecommendedAction,
-  AISeverity,
-  AIStatus,
-  AttachmentRecord,
-  MessageRecord,
-} from "../message-capture/types.js";
-export type { TextCaptureTarget } from "./messageCapture.js";
-export {
-  captureMessage,
-  registerMessageCapture,
-  setEventBroadcaster,
-} from "./messageCapture.js";
-export { messageStore } from "./messageStore.js";

services/discord-gateway/src/modules/message-capture/messageCapture.ts

@@ -1,6 +1,6 @@
 import type { Client, Message } from "discord.js-selfbot-v13";
 import { createChildLogger } from "@/shared/logger/index";
-import { config } from "../../shared/config/config.js";
+import { config } from "../../shared/config/index.js";
 import { queueMessageAnalysis } from "../ai-moderation/aiAnalyzer.js";
 import { processAttachmentUpload } from "../attachment-upload/attachmentUploader.js";
 import type { EventBroadcaster } from "../event-broadcaster/eventBroadcaster.js";