Reconcile the adaptive-context bundle (Context Frame spec, directive schema, CGP build prompt) with the protocol spec

[macanderson]

Context

The adaptive-context program merged a spec bundle into stella (docs/design/adaptive-context/: context-frame-spec.md, directive-schema.md, and a context-graph-protocol-build-prompt.md addressed at THIS repo) and into oxagen (#1074 there). Those documents define frame semantics — bounded/typed/provenance-native frames, the six questions a frame answers — that overlap the protocol surface this repo owns. Two sources of truth are already drifting.

Task

• Gap-analysis: adaptive-context frame spec + directive schema vs the current protocol spec; classify each delta as adopt-upstream / push-downstream / reject-with-rationale.
• Execute the build prompt's protocol-side items or fold them into the existing normative-track issues (Specify the write path (context/upsert) or drop the upsert capability before the freeze #5–HTTP transport: authentication and transport-security requirements #13) where they land.
• End state: the protocol repo is the single normative home; the stella docs reference it rather than restating it (companion to Make the spec self-contained: promote protocol-surface.md to the normative spec and remove dangling stella references #3's self-containment goal).

Acceptance

• A written delta table linked here; every adopted item has a spec PR or a normative-track issue; stella's bundle points at this repo for frame semantics.