fix(ncp): exit quietly on Ctrl+C instead of dumping a traceback

Ctrl+C is how you quit 'ncp web', which blocks on the UI window. It printed a
six-frame traceback ending in WaitForSingleObject, reading as a crash. Exits 130
instead.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

management/ncp.py

@@ -727,4 +727,12 @@ def main(argv) -> int:
 
 
 if __name__ == "__main__":
-    sys.exit(main(sys.argv[1:]))
+    try:
+        sys.exit(main(sys.argv[1:]))
+    except KeyboardInterrupt:
+        # Ctrl+C is how you quit `ncp web` - it waits on the UI window. Without
+        # this it printed a six-frame traceback ending in WaitForSingleObject,
+        # which reads as a crash rather than "you pressed Ctrl+C". 130 is the
+        # conventional exit status for SIGINT.
+        print()
+        sys.exit(130)