docs: move SDK development guidance to local READMEs - #2253

python/README.md:1161

• This local pytest command leaves GITHUB_ACTIONS unset. The E2E teardown therefore permits snapshot writes (python/e2e/conftest.py:40-42), and the shared proxy can contact live CAPI when a snapshot does not match. Document the replay-only invocation for routine contributor validation.
  nodejs/README.md:1126
• This local test command leaves GITHUB_ACTIONS unset, so an E2E snapshot miss falls through to the live CAPI endpoint and successful runs can rewrite snapshot files (test/harness/replayingCapiProxy.ts:185-231,560-574). Make the documented contributor workflow replay-only to avoid network calls and fixture changes during routine validation.
  dotnet/README.md:1054
• This local test invocation does not set GITHUB_ACTIONS; consequently E2ETestContext treats the run as record mode (dotnet/test/Harness/E2ETestContext.cs:476-478) and the replay proxy may contact live CAPI and write snapshots. The documented validation command should force replay-only mode.
  go/README.md:995
• test.sh does not set GITHUB_ACTIONS, so this documented local workflow allows the shared replay proxy to call live CAPI on a snapshot miss and overwrite captures. Set replay-only mode explicitly for the contributor test run.
  rust/README.md:985
• Plain cargo test does not exercise the Rust E2E suite because tests/e2e.rs is gated by test-support, and the two explicitly declared integration targets also require that feature (Cargo.toml:81-91). Enabling it also requires installing the CLI under nodejs/node_modules (tests/e2e/support.rs:1172-1203), which this workflow currently omits, so the documented test command gives a passing but incomplete validation. Install the Node runtime and run tests with test-support.

rust/README.md:975

• This command silently skips the Rust tests that are gated by test-support: session_test and protocol_version_test declare that required feature in Cargo.toml, while e2e.rs and jsonrpc_test.rs are entirely disabled without it. As written, contributors do not run the full SDK suite despite installing the E2E harness; enable test-support in the documented command.

cd rust && cargo test

dotnet/README.md:1043

• The test workflow invokes npm ci, but Node.js is not listed as a development prerequisite. The harness enforces Node ^20.19.0 || >=22.12.0, so the current prerequisites are insufficient for running this command.

Development requires [.NET SDK 10+](https://dotnet.microsoft.com/download). From the repository root:

rust/README.md:971

• The workflow below invokes npm ci, but this README does not list Node.js as a development prerequisite. Document the harness's Node ^20.19.0 || >=22.12.0 requirement so these instructions work in a fresh environment.

From the repository root:

java/README.md:425

• mvn verify executes npm ci for both test/harness and nodejs through exec-maven-plugin, but Node.js is omitted from this prerequisite list. Add the harness's Node ^20.19.0 || >=22.12.0 requirement; otherwise the documented command fails in a JDK/Maven-only environment.

Development requires JDK 25+ and [Maven](https://maven.apache.org/download.cgi). From the repository root:

python/README.md:1148

• The documented workflow invokes npm ci, but Node.js is not listed as a development prerequisite anywhere in this README. The harness requires Node ^20.19.0 || >=22.12.0, so contributors with no Node installation—or an older one—cannot follow these instructions.

Install [uv](https://docs.astral.sh/uv/), then from the repository root:

go/README.md:983

• The test workflow below requires npm, but this README only lists Go as the relevant development tool. Document the test harness's Node ^20.19.0 || >=22.12.0 requirement so a fresh contributor can run the command successfully.

From the repository root:

CONTRIBUTING.md:38

• The linked development sections generally document setup and tests, not standalone build commands, and deleting the former “All SDKs” note also removes the only explicit Node.js prerequisite even though the Python, Go, .NET, and Rust workflows below all invoke npm. Keep Node.js as a shared prerequisite here (linked to its maintained version source) and describe the delegated scope accurately.

Setup, build, and test instructions are maintained with each SDK:

java/README.md:425

• The prerequisite list omits tools required by the workflow immediately below: the commands invoke mvn, and the final validation phase requires a JDK 17 installation in addition to JDK 25. A contributor with only the listed prerequisites cannot complete the documented steps; list Maven and JDK 17 (or switch the commands to the checked-in Maven wrapper and make the JDK 17 phase explicitly optional).

Requires JDK 25 or later and a supported [Node.js version](../nodejs/README.md#prerequisites) for development. The following steps validate the artifact built with JDK 25 runs on both 25 and 17, preserving the MR-JAR behavior.