ansharma0923/semantic-intent-protocol ? reverse-engineered prompt

Build me the Semantic Intent Protocol project in Python, based on the README and the example files.

I want a small but solid reference implementation of SIP that can validate an intent envelope, match it to a registered capability, check scopes and policy, and return a deterministic execution plan instead of running anything directly. Please include the core protocol models, JSON schema validation, a capability registry, a negotiation and planning layer, policy checks, basic observability and audit logging, and a simple broker API I can run locally. Also add the protocol schema files, canonical JSON examples, and a few runnable example scripts like document retrieval and other sample intents.

Make sure the tests cover schema validation, end to end flows, and the example protocol vectors. If anything in the docs is unclear, look up current docs online if you need to. I mainly want something that feels complete enough to install, test, and use as a working reference for the protocol.