Add MVP Coordination section: code lives in citation-evidence umbrella during MVP

Documents the umbrella-first MVP decision (2026-05-24). This repo remains
INTENT-only until the anchoring interfaces stabilize through real product
use (in particular, after PDF selector round-trip is validated end-to-end).
Reaffirms: anchor depends only on engine; selector types in engine, selector
algorithms here.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

INTENT.md

@@ -404,6 +404,34 @@ This repository should be:
 
 ---
 
+## MVP Coordination — Code Lives Upstream
+
+During the umbrella-first MVP phase (decided 2026-05-24), **the source code
+for this subsystem does not live in this repository yet**. It lives in the
+umbrella repo at `citation-evidence/src/anchor/`.
+
+This INTENT.md documents the *intended* responsibilities and boundaries.
+When the anchoring interfaces have stabilized through actual MVP use — in
+particular, after PDF selector round-trip has been validated end-to-end —
+the corresponding code extracts into this repository.
+
+**Shared contracts** (selector taxonomy, viewer adapter contract, canonical
+text normalization, resolution result shape, allowed dependency edges) are
+maintained in the umbrella repo:
+
+* `citation-evidence/wiki/SharedContracts.md`
+* `citation-evidence/wiki/DependencyMap.md`
+* `citation-evidence/docs/decisions/` (ADRs)
+
+This subsystem's eventual code must not contradict those documents. Changes
+to shared contracts happen in the umbrella, not here.
+
+Under the dependency map, **`evidence-anchor` may depend only on
+`citation-engine`**. Selector *types* live in the engine; selector *creation,
+resolution, fuzzy matching, and highlight rendering* live here.
+
+---
+
 ## Guiding Statement
 
 **evidence-anchor exists to keep cited evidence attached to its source context.**