Preserve publisher-provided selection metadata through Registry ingestion?

[YE-YI7]

ToolHive's registry documentation says legacy conversion is lossless, uses the upstream MCP format, and supports publisher-provided extensions plus arbitrary custom_metadata. That looks like a clean interop seam for selection facts without changing ToolHive's own io.github.stacklok extension.

I maintain ASM, which can publish a sparse asm block under MCP Registry's publisher-provided _meta: provenance, access/quota boundaries, approval/risk, and optional links to mutable facts. ToolHive would remain authoritative for installation, isolation, policy, and runtime execution.

Would you be open to a minimal round-trip fixture/test showing that a sibling publisher-provided ASM block survives registry parsing/conversion and remains available to a downstream consumer? No ranking behavior or new required schema fields would be proposed. If the test belongs in toolhive-core rather than this repository, please point me to the preferred location.

Reference shape: https://github.com/YE-YI7/asm-spec/blob/main/examples/mcp-server-json/operational-envelope-with-asm.server.json