Add network-based IOM network configuration workflow (option 1 sub-menu)

Adds workflow_network.py implementing direct Redfish PATCH over the network
for cases where the IOM is already reachable (e.g. on DHCP) and needs
reconfiguration. Uses the same two-step PATCH workaround as the serial path:
pass 1 sets IPv4StaticAddresses, pass 2 disables DHCPv4. Option 1 in the
main menu now presents a Serial / Network / Back sub-menu before dispatching.

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

es24n_conf.py

@@ -24,6 +24,7 @@ sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)), "mod
 from ui import _c, C, banner, draw_box, ok, warn, prompt
 from workflow_check import system_check_workflow
 from workflow_firmware import firmware_update_workflow
+from workflow_network import configure_iom_network
 from workflow_restart import restart_iom_workflow
 from workflow_serial import configure_shelf
 
@@ -42,9 +43,25 @@ def main():
 
         choice = prompt("Select [1-5]")
         if choice == "1":
-            another = True
-            while another:
-                another = configure_shelf()
+            print()
+            draw_box([
+                f"  {_c(C.BOLD, '1')}  Serial Connection   (IOM not yet on the network)",
+                f"  {_c(C.BOLD, '2')}  Network Connection  (IOM reachable via management IP)",
+                f"  {_c(C.BOLD, '3')}  Back",
+            ])
+            print()
+            sub = prompt("Select [1-3]")
+            if sub == "1":
+                another = True
+                while another:
+                    another = configure_shelf()
+            elif sub == "2":
+                another = True
+                while another:
+                    another = configure_iom_network()
+            elif sub != "3":
+                warn("Please enter 1, 2, or 3.")
+                time.sleep(1)
         elif choice == "2":
             firmware_update_workflow()
         elif choice == "3":