Release LowPack 0.1.1

[devkyato]

What changed

• releases LowPack 0.1.1
• scopes CI pushes to main so version tags do not duplicate the matrix
• adds manual dispatch, least-privilege permissions, and concurrency control
• adds package project URLs, keywords, and live repository badges
• adds version-scoped checksum generation

Why

The v0.1.0 source and tag pushes launched identical CI matrices, and release
checksums could include artifacts from older versions when dist/ was reused.
This maintenance release makes the publication workflow clearer and safer.

Validation

• 30 tests passed; one Windows symlink test skipped due unavailable privileges
• Ruff passed
• strict Mypy passed
• wheel and sdist reproduced byte-for-byte across consecutive builds
• clean v0.1.1 wheel install and pack/verify/unpack smoke test passed

Closes#5.