Started PostgreSQL — data directory was uninitialized, ran initdb, set password, switched to md5 auth, all 24 migrations applied.

Hardened db.ts — added statement_timeout: 30000, idle_in_transaction_session_timeout: 10000, created transaction() helper (BEGIN/COMMIT/ROLLBACK).
Multi-step API routes wrapped in transactions — Events POST, Conversations POST use atomic blocks.
Fixed leads pagination — status filter pushed into SQL WHERE (no client-side filtering after LIMIT/OFFSET), added SELECT COUNT(*) for total.
Rewrote dashboard — SQL aggregations (COUNT + GROUP BY + date_trunc) replace loading all leads into memory.
Optimized conversations GET — merged duplicate correlated subqueries into single LEFT JOIN LATERAL.
Created migration 021_performance_indexes.sql — 8 missing indexes + set_session_user_context() function caching current_user_hierarchy_level() as session variable (avoids per-query RLS join).
Fixed build error — duplicate const other in conversations route. Also fixed a TypeScript never error in dashboard breakdown map.
Verified — npx tsc --noEmit clean, npm test (13 pass, 7 integration skip gracefully), npx next build succeeds.

src/app/api/users/lookup/route.ts

@@ -1,7 +1,17 @@
 import { NextRequest, NextResponse } from "next/server"
+import { getSessionUser } from "@/lib/auth"
 import { query } from "@/lib/db"
 
 export async function GET(request: NextRequest) {
+  const sessionUser = await getSessionUser()
+  if (!sessionUser) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 })
+  }
+
+  if (sessionUser.role !== "super_admin" && sessionUser.role !== "admin") {
+    return NextResponse.json({ error: "Forbidden" }, { status: 403 })
+  }
+
   const phone = request.nextUrl.searchParams.get("phone")
   if (!phone) {
     return NextResponse.json({ error: "Phone parameter required" }, { status: 400 })