v1.1.0

Layered architecture refactor + switched to uv.

• 4-layer package structure: theory/, composition/, protocol/, api/
• Data-driven chord factories via CHORD_TYPES dict and Chord.build()
• Song decoupled from MidiCompiler
• Section validates chord progressions at construction
• Removed all deprecated methods
• CI and dev tooling switched from poetry to uv
• 233 tests