Prepare workspace crates and client SDKs for registry publishing

[mcharytoniuk]

No description provided.

[Copilot]

Pull request overview

Prepares the Rust workspace crates and the JavaScript/Python client SDKs for registry publishing by tightening publish metadata, explicitly marking non-publishable crates, and improving SDK packaging/docs.

Changes:

• Mark internal/test-only Rust crates (and the GUI) as non-publishable via publish = false.
• Add missing crate metadata (homepage, repository) to Rust crates intended for publishing.
• Improve client SDK publishability/docs: add Python README.md/LICENSE and wire readme into pyproject.toml; update JS README imports/examples to match subpath exports.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
paddler_tests/Cargo.toml	Marks integration-test crate as non-publishable.
paddler_test_cluster_harness/Cargo.toml	Marks test harness crate as non-publishable.
paddler_openai_response_format_validator/Cargo.toml	Marks validator crate as non-publishable.
paddler_gui/Cargo.toml	Adds workspace metadata and marks GUI crate as non-publishable.
paddler_client_python/README.md	Adds PyPI-facing README with usage examples.
paddler_client_python/pyproject.toml	Sets Poetry readme to include README in published package metadata.
paddler_client_python/LICENSE	Adds Apache-2.0 license file for the Python distribution.
paddler_client_javascript/README.md	Updates import paths/examples to use subpath exports and current SSE state shape.
paddler_cli/Cargo.toml	Adds missing publish metadata fields (homepage, repository).
paddler_cli_tests/Cargo.toml	Marks CLI integration-test crate as non-publishable.
paddler_bootstrap/Cargo.toml	Adds missing publish metadata fields (homepage, repository).
Cargo.toml	Adjusts workspace dependency definition for the response-format validator crate.

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