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/backend/src/modules/analysis/analysis.schema.ts

@@ -1,10 +0,0 @@
-import { z } from "zod";
-
-export const searchQuerySchema = z.object({
-  q: z.string().default(""),
-  channelId: z.string().optional(),
-  guildId: z.string().optional(),
-  limit: z.coerce.number().int().positive().max(100).default(20),
-});
-
-export type SearchQuery = z.infer<typeof searchQuerySchema>;

services/backend/src/modules/health/health.schema.ts

@@ -1,5 +0,0 @@
-import { z } from "zod";
-
-export const healthCheckSchema = z.object({
-  verbose: z.coerce.boolean().optional().default(false),
-});

services/backend/src/modules/health/moderationMetrics.ts

@@ -1,80 +0,0 @@
-/**
- * moderationMetrics.ts
- *
- * Prometheus metrics for AI moderation pipeline.
- * Defined in backend (where prom-client is installed + /api/metrics endpoint).
- */
-import { Counter, Histogram } from "prom-client";
-
-// ── LLM Call Metrics ──
-export const llmCallsTotal = new Counter({
-  name: "moderation_llm_calls_total",
-  help: "Total LLM moderation calls",
-  labelNames: ["path", "model"] as const,
-});
-
-export const llmCallDuration = new Histogram({
-  name: "moderation_llm_call_duration_ms",
-  help: "LLM moderation call duration (ms)",
-  labelNames: ["path", "status"] as const,
-  buckets: [500, 1000, 2000, 5000, 10000, 20000, 30000, 60000, 120000],
-});
-
-export const llmTokensTotal = new Counter({
-  name: "moderation_llm_tokens_total",
-  help: "Total tokens consumed by LLM moderation",
-  labelNames: ["type"] as const,
-});
-
-// ── Cache Metrics ──
-export const moderationCacheHits = new Counter({
-  name: "moderation_cache_hits_total",
-  help: "Moderation cache hits",
-  labelNames: ["layer"] as const,
-});
-
-export const moderationCacheMisses = new Counter({
-  name: "moderation_cache_misses_total",
-  help: "Moderation cache misses",
-  labelNames: ["layer"] as const,
-});
-
-// ── Media Analysis Metrics ──
-export const mediaAnalysesTotal = new Counter({
-  name: "moderation_media_analyses_total",
-  help: "Media analyses performed",
-  labelNames: ["type"] as const,
-});
-
-export const mediaDownloadDuration = new Histogram({
-  name: "moderation_media_download_duration_ms",
-  help: "Media download duration (ms)",
-  labelNames: ["source"] as const,
-  buckets: [100, 500, 1000, 2000, 5000, 10000, 30000],
-});
-
-// ── Batch & Error Metrics ──
-export const moderationBatchSize = new Histogram({
-  name: "moderation_batch_size",
-  help: "Messages per batch",
-  labelNames: ["path"] as const,
-  buckets: [1, 5, 10, 20, 50, 100],
-});
-
-export const moderationErrors = new Counter({
-  name: "moderation_errors_total",
-  help: "Moderation errors",
-  labelNames: ["type"] as const,
-});
-
-export const webSearchCalls = new Counter({
-  name: "moderation_websearch_calls_total",
-  help: "Wikipedia web-search calls",
-  labelNames: ["status"] as const,
-});
-
-export const autoDeleteActions = new Counter({
-  name: "moderation_auto_delete_total",
-  help: "Auto-delete actions",
-  labelNames: ["action"] as const,
-});

services/backend/src/shared/commandHelper.ts

@@ -1,25 +0,0 @@
-import type { CommandReply } from "./index.js";
-import { createChildLogger } from "./logger/index.js";
-
-export { createChildLogger };
-
-/**
- * Attempt a Redis command first; if it fails or times out, fall back.
- *
- * @param commandFn  - Function that issues the publishCommand and returns the reply.
- * @param fallbackFn - Async fallback, typically reads from Redis status key.
- * @param commandLabel - Label used for logging (e.g. "voice:connect").
- */
-export async function tryCommandThenFallback<T>(
-  commandFn: () => Promise<CommandReply<T> | null>,
-  fallbackFn: () => Promise<T>,
-  commandLabel: string,
-): Promise<T> {
-  const logger = createChildLogger(`command-helper:${commandLabel}`);
-  const reply = await commandFn();
-  if (reply?.success && reply.data !== undefined && reply.data !== null) {
-    return reply.data;
-  }
-  logger.warn("discord-gateway unreachable, falling back");
-  return fallbackFn();
-}

services/backend/src/ws/index.ts

@@ -1,8 +0,0 @@
-export {
-  broadcastBinary,
-  broadcastEvent,
-  clearBroadcastFunctions,
-  setBroadcastFunctions,
-} from "./broadcast.js";
-export { startRedisBridge, stopRedisBridge } from "./redis-bridge.js";
-export { closeWebSocketServer, createWebSocketServer } from "./server.js";