Wait for IOM to come back online after restart instead of fixed sleep

A fixed 30s sleep is not enough for a full BMC boot cycle. Add
_wait_for_iom_online() which polls GET /redfish/v1/ every 15s until the
IOM responds (up to 5 minutes), then call it after every IOM restart in
both _update_iom_fw and _update_fabric_fw. This ensures the fabric card
update (and post-update validation) don't run while the IOM is still
booting and unreachable.

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

modules/workflow_firmware.py

@@ -12,6 +12,7 @@ from redfish import (
     _redfish_poll_tasks,
     _redfish_restart_iom,
     _redfish_reset_fabric,
+    _wait_for_iom_online,
     _show_fw_versions,
 )
 from ui import (
@@ -161,8 +162,12 @@ def _update_iom_fw(password: str, ip: str, iom: str, fw_path: str) -> bool:
 
     info(f"Restarting {iom}...")
     _redfish_restart_iom(password, ip, iom)   # connection drop on restart is normal
-    ok(f"{iom} restart initiated. Waiting 30s for reboot...")
-    time.sleep(30)
+    ok(f"{iom} restart initiated. Waiting for IOM to come back online...")
+    time.sleep(30)  # allow time for the IOM to begin shutting down before polling
+    if _wait_for_iom_online(password, ip):
+        ok(f"{iom} is back online.")
+    else:
+        warn(f"{iom} did not respond within 5 minutes — proceeding anyway.")
     return True
 
 
@@ -204,8 +209,12 @@ def _update_fabric_fw(password: str, ip: str, iom: str, fw_path: str) -> bool:
 
     info(f"Restarting {iom} after Fabric Card update...")
     _redfish_restart_iom(password, ip, iom)
-    ok(f"{iom} restart initiated. Waiting 30s for reboot...")
-    time.sleep(30)
+    ok(f"{iom} restart initiated. Waiting for IOM to come back online...")
+    time.sleep(30)  # allow time for the IOM to begin shutting down before polling
+    if _wait_for_iom_online(password, ip):
+        ok(f"{iom} is back online.")
+    else:
+        warn(f"{iom} did not respond within 5 minutes — proceeding anyway.")
     return True