Auto-detect firmware files in CWD for firmware update prompts

Instead of requiring a manual path entry, scan the current working
directory for files with common firmware extensions and present them
as a numbered list (most recently modified first). The last option
always allows entering a custom path, and the manual prompt is used
as a fallback if no matching files are found.

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

es24n_conf.py

@@ -680,6 +680,63 @@ def _update_fabric_fw(password: str, ip: str, iom: str, fw_path: str) -> bool:
     return True
 
 
+# ── Firmware file selection helper ────────────────────────────────────────────
+def _prompt_fw_file(label: str) -> str:
+    """
+    Scan the current working directory for firmware files and let the user
+    pick one by number, or enter a custom path as the last option.
+    Files are sorted most-recently-modified first.
+    """
+    cwd = os.getcwd()
+    FW_EXTS = {".bin", ".img", ".fw", ".hex", ".zip", ".tar", ".tgz", ".gz"}
+
+    try:
+        candidates = sorted(
+            [f for f in os.listdir(cwd)
+             if not f.startswith(".")
+             and os.path.isfile(os.path.join(cwd, f))
+             and os.path.splitext(f)[1].lower() in FW_EXTS],
+            key=lambda f: os.path.getmtime(os.path.join(cwd, f)),
+            reverse=True,
+        )
+    except OSError:
+        candidates = []
+
+    print()
+    if candidates:
+        info(f"Firmware files found in {cwd}:")
+        for i, fname in enumerate(candidates, 1):
+            sz = os.path.getsize(os.path.join(cwd, fname))
+            print(f"    {_c(C.BOLD, str(i))}  {fname}  {_c(C.DIM, f'({sz // 1024} KB)')}")
+        custom_idx = len(candidates) + 1
+        print(f"    {_c(C.BOLD, str(custom_idx))}  Enter a custom file path")
+        print()
+
+        while True:
+            choice = prompt(f"Select {label} [1-{custom_idx}]")
+            if choice.isdigit():
+                idx = int(choice)
+                if 1 <= idx <= len(candidates):
+                    path = os.path.join(cwd, candidates[idx - 1])
+                    sz   = os.path.getsize(path)
+                    ok(f"Selected: {candidates[idx - 1]} ({sz // 1024} KB)")
+                    return path
+                if idx == custom_idx:
+                    break
+            warn(f"Please enter a number between 1 and {custom_idx}.")
+    else:
+        info(f"No firmware files found in {cwd}.")
+
+    # Manual path entry
+    while True:
+        path = prompt(f"Path to {label}")
+        if os.path.isfile(path):
+            sz = os.path.getsize(path)
+            ok(f"File: {path} ({sz // 1024} KB)")
+            return path
+        warn(f"File not found: {path}")
+
+
 # ── Firmware Update Workflow ──────────────────────────────────────────────────
 def firmware_update_workflow():
     """
@@ -746,24 +803,10 @@ def firmware_update_workflow():
     fabric_fw_path = ""
 
     if update_iom:
-        print()
-        while True:
-            iom_fw_path = prompt("Path to IOM firmware file")
-            if os.path.isfile(iom_fw_path):
-                sz = os.path.getsize(iom_fw_path)
-                ok(f"File: {iom_fw_path} ({sz // 1024} KB)")
-                break
-            warn(f"File not found: {iom_fw_path}")
+        iom_fw_path = _prompt_fw_file("IOM firmware file")
 
     if update_fabric:
-        print()
-        while True:
-            fabric_fw_path = prompt("Path to Fabric Card firmware file")
-            if os.path.isfile(fabric_fw_path):
-                sz = os.path.getsize(fabric_fw_path)
-                ok(f"File: {fabric_fw_path} ({sz // 1024} KB)")
-                break
-            warn(f"File not found: {fabric_fw_path}")
+        fabric_fw_path = _prompt_fw_file("Fabric Card firmware file")
 
     print()
     warn("For HA systems: update the passive IOM first.")