chore: add MIT license

[tino-cmd]

Summary

• add a root MIT LICENSE matching openbox-sdk-ts
• include LICENSE in Python wheel and source distribution metadata
• link the license from README
• remove the deprecated MIT Trove classifier in favor of the SPDX expression

Verification

• git diff --check
• built the wheel and source distribution with uv build
• confirmed both artifacts contain LICENSE
• confirmed wheel metadata reports License-Expression: MIT and License-File: LICENSE
• confirmed the license SHA-256 matches openbox-sdk-ts