fix(skill): forward CLI flags through $ARGUMENTS to Python script

Remove double quotes around $ARGUMENTS in SKILL.md so bash word-splits
the expansion, and change argparse topic from nargs="?" to nargs="*"
so multi-word topics still work. Also document --store, --include-web,
--diagnose, and --timeout flags in the Options section.

Closes #36

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

scripts/last30days.py

@@ -1037,7 +1037,7 @@ def main():
     parser = argparse.ArgumentParser(
         description="Research a topic from the last N days on Reddit + X"
     )
-    parser.add_argument("topic", nargs="?", help="Topic to research")
+    parser.add_argument("topic", nargs="*", help="Topic to research")
     parser.add_argument("--mock", action="store_true", help="Use fixtures")
     parser.add_argument(
         "--emit",
@@ -1122,6 +1122,7 @@ def main():
     )
 
     args = parser.parse_args()
+    args.topic = " ".join(args.topic) if args.topic else None
 
     # Enable debug logging if requested
     if args.debug: