refactor: extract inline middleware from index.ts into separate modules (#85)

- Extract update middleware to routes/update.ts
- Extract health middleware and version logic to routes/health.ts
- Extract shutdown logic to services/shutdown.ts
- Extract gateway init to services/gateway-bootstrap.ts
- Remove unused variables, fix duplicate app creation
- Bump version to 0.4.0

index.ts: 260 lines → 80 lines

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "hermes-web-ui",
-  "version": "0.3.8",
+  "version": "0.4.0",
   "description": "Web dashboard for Hermes Agent — multi-platform AI chat, session management, scheduled jobs, usage analytics & channel configuration (Telegram, Discord, Slack, WhatsApp)",
   "repository": {
     "type": "git",