Editable Install failure due to missin setup.py / outdated pip

[kartik761]

Description

This PR fixes the development installation issue where pip install -e . fails because:

• The repo was missing setup.py, required for editable installs on older pip versions.
• Editable installs via pyproject.toml alone require pip >= 21.3.

With this fix, developers can now install the SDK in editable mode and make local changes during development.

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Changes Made

• Added a minimal setup.py for backward compatibility
• Verified editable install works with pip >=21.3
• Updated README instructions to remind developers to upgrade pip before running pip install -e . (optional)

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Steps to Test / Verify

1. Clone the repository
2. Create and activate a virtual environment:

   python -m venv venv
   .\venv\Scripts\Activate.ps1

[kartik761]

Hi! this PR fixes the issue "editable install issue by adding a minimal setup.py." Verified that pip install -e . works with pip 21.3.
Thanks if you reviewed