[All SDKs] Add a top-level Makefile in each SDK to simplify running tests and linters

[SoulPancake]

Checklist

• [x] I agree to the terms within the OpenFGA Code of Conduct.

Describe the problem you'd like to have solved

Currently, contributors to each SDK (Go, JS, Python, etc.) have to manually figure out how to run tests and lint checks — often by looking through CI workflows or project-specific docs. This creates friction for new contributors who want to verify their changes locally and makes it harder to maintain consistency across SDKs.

Having a standardized Makefile in each SDK repository would simplify the local development process by providing a unified interface for running tests and linters.

Describe the ideal solution

Each SDK repository (e.g., go-sdk, js-sdk, python-sdk, etc.) should include a top-level Makefile that defines common developer commands such as:

test:
	<language_specific_test_command>

lint:
	<language_specific_linter_command>

fmt:
	<language_specific_formatter_command>

The way much of this is done already exists in the sdk-generator Makefile.

This gives contributors a consistent and predictable workflow while working in the SDK changes:

make test   # run all tests
make lint   # run all linters
make fmt    # format code

Alternatives and current workarounds

No response

References

No response

Additional context

The proposed Makefile setup would:

• Simplify onboarding for new contributors
• Standardize test and lint commands across all SDKs
• Improve local-to-CI consistency
• Allow easy updates to contributor documentation (e.g., “Run make test before pushing changes”)