Implement CE-WP-0003 T01-T08: form binding + visual guide overlay

T01 EvidenceLink/EvidenceSet types
  - src/shared/evidence-link.ts: status (§2.4), relation (§2.5), target
  - src/shared/evidence-set.ts: ordered group + activeEvidenceItemId
  - enum-conformance test parses SharedContracts.md and asserts the
    runtime lists match exactly

T02 Binding service + in-memory link repo + active-state machine
  - src/binder/repos/in-memory-links.ts: Map-backed EvidenceLinkRepository
  - src/binder/services/bindings.ts: link/unlink/list/update/setActive
    emitting §4 EvidenceLinkCreated / EvidenceLinkUpdated /
    EvidenceItemActivated
  - src/binder/state/active.ts: (target, evidence, annotation) reducer
    + ActiveStateProvider + useActiveState hook
  - extended engine/events/types.ts with EvidenceLinkCreated,
    EvidenceLinkUpdated, FormFieldActivated payloads

T03 Rect registry (SharedContracts §7 — contract FROZEN)
  - src/binder/visual-guide/rect-registry.ts: register/getRect/subscribe
    + invalidate + getVersion for useSyncExternalStore
  - events.ts: scroll/resize/focus pumps via window + ResizeObserver +
    IntersectionObserver, rAF-throttled
  - react-hooks.ts: RectRegistryProvider, useRegisterRect(kind,id,ref),
    useRectRegistryVersion

T04 Form schema + renderer
  - src/app/forms/demo-schema.ts: text/textarea/date minimal schema
  - src/binder/FormRenderer.tsx: renders schema, each field registers
    as rect kind="field"; active field gets aria-current="true"
  - placed in binder/ (not work/) because work cannot import binder per
    DependencyMap.md §2 and the renderer needs the rect-registry hook;
    workplan T04 was amended in-place to document this

T05 Side-by-side Forms layout + click-to-link
  - src/app/forms/FormsApp.tsx + src/app/App.tsx top-bar router with
    hash route #/forms/demo
  - BinderProvider mounted at app root so links survive tab switching
  - stage-evidence-then-click-field linking interaction with banner
    + per-field link-count chip

T06 Active-evidence cycling
  - src/app/forms/ActiveEvidenceChips.tsx: chips per active target,
    Tab cycles natively, first chip auto-activates on field focus,
    each chip registers as rect kind="evidence-card"
  - ScrollBridge in FormsApp wires activeAnnotationId to viewer scroll
  - EvidenceSidebar + EvidenceStrip highlight the active item via the
    new useLastActivatedEvidence hook in work/EngineContext

T07 SVG visual-guide overlay
  - src/binder/visual-guide/Overlay.tsx: single fixed-positioned SVG,
    draws field→card and card→highlight bezier curves for the active
    triple, rAF-throttled via the registry
  - src/anchor exposes getHighlightClientRects(annotationId); the
    spike viewer wraps highlights in [data-highlight-id] so the helper
    can locate them
  - src/app/forms/HighlightRectBridge.tsx: registers the active
    annotation's rect via that helper

T08 End-to-end test (PRD scenario steps 5-9)
  - tests/integration/forms-overlay-e2e.dom.test.tsx: full path from
    Review-mode capture through Forms-mode link to active triple +
    aria-current assertions + 2 SVG paths in the overlay
  - additional integration coverage: forms-link-flow + forms-active-cycling

Gates: typecheck ✓ · lint ✓ · build ✓ · 152/152 tests across 21 files.

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

src/anchor/index.ts

@@ -1,6 +1,7 @@
 export * from "./types";
 export {
   PdfSpikeViewer,
+  getHighlightClientRects,
   selectorsFromPdfCapture,
   type PdfSpikeViewerProps,
   type StoredAnnotation,

src/anchor/pdf-viewer-adapter-spike.tsx

@@ -113,13 +113,50 @@ function captureFromPdfSelection(sel: PdfSelection): PdfSelectionCapture {
  */
 function SpikeHighlightContainer(): ReactNode {
   const { highlight, isScrolledTo } = useHighlightContainerContext();
+  // Wrap the highlight in a data-tagged container so the visual-guide
+  // overlay's HighlightRectBridge can locate it via DOM query. The
+  // wrapper uses display: contents so it doesn't affect layout — the
+  // bounding rect is gathered from the live TextHighlight children at
+  // query time.
   return (
-    <MonitoredHighlightContainer>
-      <TextHighlight highlight={highlight} isScrolledTo={isScrolledTo} />
-    </MonitoredHighlightContainer>
+    <div data-highlight-id={highlight.id} style={{ display: "contents" }}>
+      <MonitoredHighlightContainer>
+        <TextHighlight highlight={highlight} isScrolledTo={isScrolledTo} />
+      </MonitoredHighlightContainer>
+    </div>
   );
 }
 
+/**
+ * Resolve the rendered DOM rect for a highlight by data attribute, or
+ * `null` if the highlight isn't currently rendered (e.g. its page hasn't
+ * scrolled into view). Used by `app/forms/HighlightRectBridge` to feed
+ * the rect registry as kind="highlight".
+ *
+ * `display: contents` on the wrapper means it has no box of its own; we
+ * union the rects of its children. For TextHighlight that's typically
+ * one rect per line.
+ */
+export function getHighlightClientRects(annotationId: string): DOMRect | null {
+  if (typeof document === "undefined") return null;
+  const wrapper = document.querySelector(`[data-highlight-id="${CSS.escape(annotationId)}"]`);
+  if (!wrapper) return null;
+  const rects = wrapper.getClientRects();
+  if (rects.length === 0) return null;
+  let left = Infinity;
+  let top = Infinity;
+  let right = -Infinity;
+  let bottom = -Infinity;
+  for (const r of Array.from(rects)) {
+    left = Math.min(left, r.left);
+    top = Math.min(top, r.top);
+    right = Math.max(right, r.right);
+    bottom = Math.max(bottom, r.bottom);
+  }
+  if (!isFinite(left)) return null;
+  return new DOMRect(left, top, right - left, bottom - top);
+}
+
 export interface PdfSpikeViewerProps {
   /** URL of the PDF to load (served by Vite dev server). */
   readonly pdfUrl: string;