fix(benchmark): scheme validation to ollama-url (closes #166) (#274)

Add urllib.parse.urlparse to benchmark-local.py and validate that the
provided --ollama-url uses either the http or https scheme.

Fix arbitrary URI handling where the script could previously access
local files (file://) or other unsupported protocols. If the scheme
is invalid, parser.error is called to exit cleanly with a clear message.

benchmarks/benchmark-local.py

@@ -15,6 +15,7 @@ import json
 import re
 import time
 import urllib.request
+import urllib.parse
 from pathlib import Path
 
 ROOT = Path(__file__).parent.parent
@@ -149,6 +150,11 @@ def main():
     parser.add_argument("--repeat",     type=int, default=1, help="Runs per cell; median reported (default: 1)")
     parser.add_argument("--ollama-url", default="http://localhost:11434", help="Ollama base URL")
     args = parser.parse_args()
+
+    parsed_url = urllib.parse.urlparse(args.ollama_url)
+    if parsed_url.scheme not in ("http", "https"):
+        parser.error(f"Invalid --ollama-url scheme: '{parsed_url.scheme}'. Only 'http' and 'https' are supported.")
+
     run(args.model, args.repeat, args.ollama_url)