.NET: Memory portability between agents — verified memory bundles with chain of custody (complements A2A)

Maintainer of [cognicore-env](https://github.com/cognicore-dev/cognicore-env) here (open-source agent memory layer, MIT, MCP-compatible) — this is a proposal, happy to do the work as an example.

Agent Framework's A2A support moves tasks between agents; MCP moves tools. What nothing moves is verified knowledge. When agent A hands off to agent B today, B starts from zero, or teams bolt on a shared store with no provenance — no way to know which agent learned a fact, what evidence it was based on, or how stale it is. In multi-team setups that produces a specific failure mode we have measured: on conflicting facts, models do not decline — they confidently report the wrong one (a practitioner running six teams on shared memory reported 33 percent accuracy on conflict questions without ownership rules).

Proposal: a memory transfer component that emits and consumes sealed bundles. Each memory carries proof (command, result, exit code, output hash) and a chain of custody; receivers import foreign memories in an observed state that requires local re-verification; trust decays across hops. The design now includes owner-per-concept and validity intervals (a convention verified in March is not evidence about April) from that same multi-team review.

The interesting framework-specific angle: a bundle crossing a .NET agent and a Python agent proves the format is runtime-portable — exactly the cross-runtime story Agent Framework is built around. Our transfer layer is implemented and tested across four platforms.

Happy to contribute a working example. Would this belong in samples, or do you see it as a component discussion first?

Start with the proposal's question about placing the work in samples versus treating it as a component discussion. Review the described sealed bundles, chain of custody, local re-verification, ownership, validity intervals, and four-platform implementation. Done means the framework-specific scope and contribution location are agreed.

Written by the indexing model from the issue text.