ntegration: memory transfer store for LangChain/LangMem export and import verified agent memory

### Submission checklist - [x] This is a feature request, not a bug report or usage question. - [x] I added a clear and descriptive title that summarizes the feature request. - [x] I used the GitHub search to find a similar feature request and didn't find it. - [x] I checked the LangChain documentation and API reference to see if this feature already exists. - [x] This is not related to the langchain-community package. ### Package (Required) - [x] langchain - [x] langchain-openai - [x] langchain-anthropic - [x] langchain-classic - [x] langchain-core - [x] langchain-model-profiles - [x] langchain-tests - [x] langchain-text-splitters - [x] langchain-chroma - [x] langchain-deepseek - [x] langchain-exa - [x] langchain-fireworks - [x] langchain-groq - [x] langchain-huggingface - [x] langchain-mistralai - [x] langchain-nomic - [x] langchain-ollama - [x] langchain-openrouter - [x] langchain-perplexity - [x] langchain-qdrant - [x] langchain-typesafe - [x] langchain-xai - [x] Other / not sure / general ### Feature Description Maintainer of [cognicore-env](https://github.com/cognicore-dev/cognicore-env) (open-source, MIT) — this is an integration offer for the LangChain ecosystem, not a core feature request. LangMem covers memory inside the LangChain ecosystem well. The gap outside it: memory portability. A LangChain agent's learned knowledge cannot move to another deployment, another framework, or a Claude Code agent with any provenance — and when teams hand-roll export, they ship plain text with no state, history, or expiry. Proposal: a transfer store in the LangChain integration ecosystem. The bundle format carries per memory: proof (command, result, exit code, output hash), chain of custody across every agent that touched it, observed-until-reverified import semantics, trust decay across unverified hops, validity intervals, and owner-per-concept conflict rules. The last two came from a public design review with operators running six teams on shared memory — without them, …