Required request comments and typed graph Trace Chain (conformance #99) #41

Implement request-owned required intent and typed per-entity graph Trace Chain.

Cross-language design: https://github.com/teaql/teaql-conformance/blob/main/design/runtime-trace-chain-conformance.md

Query requests must own a non-blank comment and purpose. Mutation requests must own a non-blank comment; descendants inherit it and may append local business reasons. Each mutation item carries its own root-to-leaf typed audit lineage through SQL metadata and committed safe audit delivery. SQL execution path and business audit lineage remain distinct.

Acceptance includes missing/blank rejection before policy/provider, branch and batch isolation, same numeric ID across entity types, deleted-child local reasons, allocated IDs, concurrent graphs sharing a Context, failure/readback evidence, and privacy-preserving export. Run runtime source tests and examples against local dependencies and retain exact revisions and outcomes. Generated adapter changes are tracked in teaql-code-gen; no release is authorized by this issue alone.