fix: only parse HP/Aruba banner lines in parse_model_from_version

Guard against show version outputs that start with "Image stamp:" or
other non-banner lines — return ("", "") when the first line doesn't
begin with HP/HPE/Aruba.

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

napalm_procurve/parsers.py

@@ -195,11 +195,18 @@ def parse_model_from_version(output: str) -> tuple[str, str]:
       ``HP J9565A 2520G-8-PoE Switch`` → ("2520G-8-PoE", "J9565A")
       ``HP J9298A Switch 2520G-8-PoE`` → ("2520G-8-PoE", "J9298A")
       ``Aruba 2530-8-PoE+ Switch``     → ("2530-8-PoE+", "")
+
+    Returns ("", "") when the first line is not an HP/Aruba device banner
+    (e.g. when show version starts with "Image stamp:" on newer Aruba).
     """
     first = output.strip().splitlines()[0] if output.strip() else ""
     if not first:
         return "", ""
 
+    # Only process lines that start with an HP/Aruba product banner
+    if not re.match(r"\s*(?:HP|HPE|Aruba)\b", first, re.I):
+        return "", ""
+
     # Extract J-code part number
     _PN_RE_V = re.compile(r"\b(J\d{4}[A-Z]{1,2})\b")
     pn_match = _PN_RE_V.search(first)