Confirm success and pause before returning to main menu after firmware update

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

modules/workflow_firmware.py

@@ -297,6 +297,7 @@ def firmware_update_workflow():
     rule("Post-Update Firmware Validation")
     _show_fw_versions(targets)
 
+    ok("Firmware update complete.")
     print()
     draw_box([
         f"{_c(C.YEL, 'IMPORTANT -- For HA (Dual-Controller) Systems:')}",
@@ -306,3 +307,4 @@ def firmware_update_workflow():
         "  2. Re-run this tool to update the other controller.",
     ], colour=C.YEL)
     print()
+    prompt("Press Enter to return to main menu")