feat: add Koa2 BFF server, CLI management, sessions CLI integration, and logs page

- Add Koa2 BFF layer for API proxy, file upload, session management
- Auto-check and enable api_server in ~/.hermes/config.yaml on startup
- Integrate sessions with Hermes CLI (list, get, delete)
- Add Logs page with level filtering, log file selection, and search
- Add CLI commands: start/stop/restart/status for daemon management
- Unify package.json for frontend and server dependencies
- Default port changed to 8648

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

server/src/config.ts

@@ -0,0 +1,10 @@
+import { resolve } from 'path'
+import { tmpdir } from 'os'
+
+export const config = {
+  port: parseInt(process.env.PORT || '8648', 10),
+  upstream: process.env.UPSTREAM || 'http://127.0.0.1:8642',
+  uploadDir: process.env.UPLOAD_DIR || resolve(tmpdir(), 'hermes-uploads'),
+  dataDir: resolve(__dirname, '..', 'data'),
+  corsOrigins: process.env.CORS_ORIGINS || '*',
+}