fix(salary): reject non-finite converter baselines (#665)

* fix(salary): reject non-finite converter baselines

* changelog: place the #665 entry under [Unreleased]

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: GAPIT-KIENTH\kienth <kienth@gapit.com.vn>
Co-authored-by: Mads Lorentzen <madslorentzen_17@hotmail.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

tools/convert_salary_excel.py

@@ -398,6 +398,9 @@ def main():
     )
     args = parser.parse_args()
 
+    if not math.isfinite(args.baseline):
+        parser.error("--baseline must be a finite number")
+
     excel_path = Path(args.excel_file)
     if not excel_path.exists():
         print(f"Error: File not found: {excel_path}", file=sys.stderr)