docs: compare Nano with Python

[AdityaRajhans-07]

Why does this change belong in Nano?

What changed?

Validation

• Focused tests passed.
• python -m pytest -q passed.
• Documentation and examples match the shipped behavior.

Boundary check

• The change preserves deterministic reference execution for identical graph/frame inputs.
• The change does not bypass the host-owned DecisionGate or add external actuation to Nano source/runtime.
• If this adds a strategy, it includes paired .nano and _ir.json files plus documented host signal conventions.

[AetherAI3]

Closing as stale: red CI, untouched since Aug 13. Reopen from a fresh branch if the Nano-vs-Python comparison is still wanted.