feat(backend): implement all missing endpoints, real analytics queries, and WebSocket server

- Replace stub analytics.repository.ts with real PostgreSQL queries using pg.Pool
- Add /api/guilds, /api/config, /api/auth/login, /api/ui-state (GET/POST)
- Add /api/review, /api/recordings, /api/analysis/search
- Add /api/messages/:id/reanalyze endpoint
- Add /api/analytics/heatmap and /api/analytics/topics
- Implement media routes (stub responses, backend has no Discord voice client)
- Add WebSocket server at /ws with heartbeat and broadcast functions
- Fix analytics route paths to match frontend contract (dual paths for backward compat)
- Export getPool() from database module for raw SQL queries
- Register all new routers in app.ts

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

services/backend/src/modules/analysis/analysis.routes.ts

@@ -0,0 +1,27 @@
+import type { Request, Response, Router } from "express";
+import express from "express";
+import { createChildLogger } from "../../shared/logger/index.js";
+import { asyncHandler } from "../../shared/middlewares/index.js";
+import { analysisService } from "./analysis.service.js";
+
+const logger = createChildLogger("analysis.routes");
+
+export function createAnalysisRouter(): Router {
+  const router = express.Router();
+
+  // GET /api/analysis/search
+  router.get(
+    "/analysis/search",
+    asyncHandler(async (req: Request, res: Response) => {
+      const q = (req.query.q as string) || "";
+      const channelId = (req.query.channelId as string) || undefined;
+      const limit = Number(req.query.limit) || 20;
+
+      logger.debug({ q, channelId, limit }, "Analysis search requested");
+      const result = await analysisService.search({ q, channelId, limit });
+      res.json(result);
+    }),
+  );
+
+  return router;
+}

services/backend/src/modules/analysis/analysis.service.ts

@@ -0,0 +1,73 @@
+import { sql } from "drizzle-orm";
+import { getDatabase } from "../../shared/database/index.js";
+import { config } from "../../shared/config/index.js";
+import { createChildLogger } from "../../shared/logger/index.js";
+
+const logger = createChildLogger("analysis.service");
+
+export interface AnalysisSearchQuery {
+  q?: string;
+  channelId?: string;
+  limit?: number;
+}
+
+export class AnalysisService {
+  async search(query: AnalysisSearchQuery) {
+    const db = getDatabase();
+    const { q = "", channelId, limit = 20 } = query;
+    const guildId = config.MONITOR_GUILD_ID;
+
+    logger.debug({ q, channelId, limit, guildId }, "Searching analysis");
+
+    const searchPattern = `%${q}%`;
+    const limitVal = limit;
+
+    let sqlQuery;
+    if (channelId && guildId) {
+      sqlQuery = sql`
+        SELECT id, guild_id, channel_id, user_id, username, avatar_url,
+               content, type, created_at, ai_status, ai_severity, ai_confidence
+        FROM messages
+        WHERE guild_id = ${guildId}
+          AND channel_id = ${channelId}
+          AND content ILIKE ${searchPattern}
+        ORDER BY created_at DESC
+        LIMIT ${limitVal}
+      `;
+    } else if (channelId) {
+      sqlQuery = sql`
+        SELECT id, guild_id, channel_id, user_id, username, avatar_url,
+               content, type, created_at, ai_status, ai_severity, ai_confidence
+        FROM messages
+        WHERE channel_id = ${channelId}
+          AND content ILIKE ${searchPattern}
+        ORDER BY created_at DESC
+        LIMIT ${limitVal}
+      `;
+    } else if (guildId) {
+      sqlQuery = sql`
+        SELECT id, guild_id, channel_id, user_id, username, avatar_url,
+               content, type, created_at, ai_status, ai_severity, ai_confidence
+        FROM messages
+        WHERE guild_id = ${guildId}
+          AND content ILIKE ${searchPattern}
+        ORDER BY created_at DESC
+        LIMIT ${limitVal}
+      `;
+    } else {
+      sqlQuery = sql`
+        SELECT id, guild_id, channel_id, user_id, username, avatar_url,
+               content, type, created_at, ai_status, ai_severity, ai_confidence
+        FROM messages
+        WHERE content ILIKE ${searchPattern}
+        ORDER BY created_at DESC
+        LIMIT ${limitVal}
+      `;
+    }
+
+    const { rows } = await db.execute(sqlQuery);
+    return { results: rows };
+  }
+}
+
+export const analysisService = new AnalysisService();