Add conformant Python implementation

[Jason-Doyle]

Summary

• add an independent Python 3.11+ verifier and worldcut-py CLI for protocol 0.1 / engine 0.1.2
• mirror and enforce the normative conformance corpus, immutable parsed inputs, detached verification results, bounded integer-cost planning, and exact canonical digests
• ship typed wheel/sdist packaging with isolated consumer tests, Python 3.11-3.14 CI, Python CodeQL coverage, and pip Dependabot updates

Quality gate

• Ruff format and lint
• strict mypy
• 54 pytest tests including Hypothesis transport/canonicalization properties
• exact conformance vectors and manifest hashes
• clean wheel contents, Twine metadata, isolated wheel CLI smoke, and standalone extracted-sdist tests
• differential review against the TypeScript reference over 3,150 targeted and randomized inputs with no protocol divergences
• root TypeScript release checks, Go tests/vet, Linux race detector, and actionlint