Add Restart IOM option to main menu (option 4)

New workflow_restart.py supports restarting IOM1 or IOM2 via:
- Network: prompts for password, IP, and IOM, sends GracefulRestart
- Serial: detects device, logs in, prompts for IOM, sends curl restart

Exit shifted from option 4 to option 5.

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

CLAUDE.md

@@ -32,6 +32,7 @@ modules/
     workflow_serial.py      ← Serial-based IOM network configuration workflow
     workflow_firmware.py    ← IOM and Fabric Card firmware update workflow
     workflow_check.py       ← Read-only system check (network settings + firmware versions)
+    workflow_restart.py     ← Restart IOM via network or serial
 ```
 
 `es24n_conf.py` adds `modules/` to `sys.path` at startup so all inter-module imports work without a package structure.