add zeromq package (#7)

Static build of libzmq 4.3.5 providing headers and library for
C/C++ projects that link against zmq.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

zeromq/zeromq/__init__.py

@@ -0,0 +1,10 @@
+import os
+
+DIR = os.path.join(os.path.dirname(__file__), "install")
+LIB_DIR = os.path.join(DIR, "lib")
+INCLUDE_DIR = os.path.join(DIR, "include")
+
+
+def smoketest():
+  assert os.path.isfile(os.path.join(LIB_DIR, "libzmq.a")), "libzmq.a not found"
+  assert os.path.isfile(os.path.join(INCLUDE_DIR, "zmq.h")), "zmq.h not found"