Runs the local release-readiness smoke checks used before pushing a release tag.
mix release.smokeThis task does not publish anything. It runs deterministic root release checks,
root and MCP memory soak checks, then builds and smoke-tests the sibling
mcp_server release binary.
The MCP smoke builds mcp_server with MIX_ENV=prod mix release --overwrite
and then runs mcp_server/test/integration/release_stdio_test.exs against the
built binary. Set PTC_SOAK_ITERATIONS to tune soak duration; it defaults to
3000.