intent(SHARD-WP-0013 T4): ratify additive native engine — headless, API-first, agent-optimized

Ratified by tegwick (decision 84ffdb48 resolved). INTENT.md amended: native
reference wiki-engine as a canonical-mode shard backend, reframed as HEADLESS &
API-FIRST — small typed-extension core optimized for integrating heterogeneous
data sources and efficient agent/automation access; no bundled UI. Edits:
Primary Utility framing + bullet, non-goal clarifier, new Design Principle,
Stability Note amendment. SCOPE.md: engine core in scope, UI/rendering out.
Orchestrator role unchanged; union-without-erasure + shard sovereignty preserved.
Marks T4 done; unblocks T5 (WikiEngineCoreArchitecture.md).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

SCOPE.md

@@ -32,11 +32,15 @@ Learnings update both SCOPE and INTENT where necessary.
 - Authorization model design (delegated authentication, core authorization).
 - Shard adapter contract and wiki page model (to be specified, then implemented).
 - Git-backed coordination journal for information spaces.
+- A **native, headless, API-first wiki-engine core** (small typed-extension core, as a
+  canonical-mode shard backend) — design via SHARD-WP-0013; optimized for data-source
+  integration and agent access.
 - State Hub workplan registration and consistency sync.
 
 ## Out Of Scope (today)
 
-- A standalone wiki engine UI or rendering pipeline.
+- A wiki-engine **UI or rendering pipeline** (the engine is headless/API-first; presentation
+  is a consumer concern). A bundled standalone UI is not provided.
 - Authentication, credential storage, or user directory implementation.
 - Hard-coded editorial, sync, or conflict-resolution policy.
 - Generic file mirroring independent of wiki-page semantics.