Replaces the external jrpces binary dependency with a self-contained
Python script. The server supports TCP (newline-delimited JSON, port 4321)
and UDP (port 4323), handles JSON-RPC 1.0 and 2.0, and implements:
- echo(*args) -> [args, {}]
- unknown methods -> error {code: -32000, message: "function not found"}
test.tum is updated to launch jrpc_echo_server.py via python3 and wait
for the "ready" readiness message before running tests.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
