security: address assessment findings and bump to v2026.3.11

- C1: Disable Swagger UI in production (env gate)
- M1+M2: Add Helmet.js for security headers (CSP, X-Frame-Options,
  X-Content-Type-Options, Referrer-Policy) and remove X-Powered-By
- H2: Add @nestjs/throttler rate limiting (5 req/min on login/register)
- M4: Remove orgSchema from JWT payload and client-side storage;
  tenant middleware now resolves schema from orgId via cached DB lookup
- L1: Fix Chatwoot user identification (read from auth store on ready)
- Remove schemaName from frontend Organization type and UI displays

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/package.json

@@ -1,6 +1,6 @@
 {
   "name": "hoa-ledgeriq-frontend",
-  "version": "2026.03.10",
+  "version": "2026.3.11",
   "private": true,
   "type": "module",
   "scripts": {