Refine evidence UX: sidebar capture form, inline edit, click highlight

Significant UX iteration:

Visual palette
- Debug text-layer overlay flips from yellow to light grey so it no
  longer collides with the evidence highlight colour.
- New highlight-styles.css matches the sidebar's #fff8d6/#e0c050
  palette so a passage marked in the document and its sidebar card
  speak the same visual language.
- Active (focused) evidence: same fill, thick #b78b1c outline on both
  the highlight and the sidebar card. Library's red --scrolledTo
  box-shadow is suppressed.

Activation model
- Click an evidence card in the sidebar → activates that item +
  scrolls the viewer to the passage + thickens the borders (existing
  behaviour, now visually clearer).
- Click a highlight in the document → activates the evidence that
  owns that annotation. New `findByAnnotationId()` on EvidenceService
  is the reverse lookup. Wired through a new `onHighlightClicked`
  prop on PdfSpikeViewer + `activeAnnotationId` prop that drives the
  data-ce-active attribute on the highlight wrapper.

Inline edit
- Each evidence card has a ✎ button that flips the card into an
  inline form with the citation (quote) and commentary fields.
- Saving calls a new `AnnotationService.updateQuote()` +
  existing `EvidenceService.updateCommentary()`. The selectors are
  untouched, so the marked passage in the document stays put — the
  inline hint says so explicitly.
- New `AnnotationUpdated` event added to the engine event vocabulary
  (SharedContracts.md §4 updated).

Capture form placement
- The yellow "New annotation" toolbar that lived above the viewer is
  gone. A new InlineCaptureForm component is now slotted into the
  sidebar between the cards that bracket the new selection in
  document flow (sorted by page + y of the first PdfRectSelector).
  If the new selection is before all existing evidence it appears at
  the top; if after all of them, at the bottom.
- The legacy AnnotationToolbar.tsx is removed; the public surface
  re-exports `InlineCaptureForm` instead.

Test updates
- tests/integration/citation-card-export-e2e.dom.test.tsx: switched
  to the seed-session helper (matches the other E2Es) since the
  fixture-button click path is gone.

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

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

@@ -28,6 +28,7 @@ import {
 } from "react-pdf-highlighter-plus";
 import "react-pdf-highlighter-plus/style/style.css";
 import "react-pdf-highlighter-plus/style/pdf_viewer.css";
+import "./highlight-styles.css";
 import "./debug-textlayer.css";
 
 import type { NormalizedRect, Selector } from "@shared/selector";
@@ -112,20 +113,34 @@ function captureFromPdfSelection(sel: PdfSelection): PdfSelectionCapture {
  * For the spike, no editing tooling — just visual proof of "did the saved
  * coordinates land on the right passage on the right page after reload?"
  */
-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 (
-    <div data-highlight-id={highlight.id} style={{ display: "contents" }}>
-      <MonitoredHighlightContainer>
-        <TextHighlight highlight={highlight} isScrolledTo={isScrolledTo} />
-      </MonitoredHighlightContainer>
-    </div>
-  );
+interface HighlightContainerProps {
+  readonly activeAnnotationId: string | null | undefined;
+  readonly onHighlightClicked: ((annotationId: string) => void) | undefined;
+}
+
+function makeSpikeHighlightContainer(props: HighlightContainerProps) {
+  return function SpikeHighlightContainer(): ReactNode {
+    const { highlight, isScrolledTo } = useHighlightContainerContext();
+    const isActive = props.activeAnnotationId === highlight.id;
+    return (
+      <div
+        data-highlight-id={highlight.id}
+        data-ce-active={isActive ? "true" : "false"}
+        style={{ display: "contents" }}
+        onClickCapture={(e) => {
+          // Click-capture so the click registers before the library's
+          // built-in selection-clearing logic eats it. Stop propagation
+          // so the highlight click doesn't also start a new selection.
+          e.stopPropagation();
+          props.onHighlightClicked?.(highlight.id);
+        }}
+      >
+        <MonitoredHighlightContainer>
+          <TextHighlight highlight={highlight} isScrolledTo={isScrolledTo} />
+        </MonitoredHighlightContainer>
+      </div>
+    );
+  };
 }
 
 /**
@@ -168,7 +183,18 @@ export interface PdfSpikeViewerProps {
   /** Annotation id to scroll to and highlight on mount, if any. */
   readonly scrollToAnnotationId?: string;
   /**
-   * When true, paint the PDF text-layer spans in yellow so it's
+   * Annotation id currently focused. The matching highlight gets a
+   * thicker border (see highlight-styles.css). `null`/undefined means
+   * "no active highlight".
+   */
+  readonly activeAnnotationId?: string | null;
+  /**
+   * Called when the user clicks an existing highlight in the page.
+   * The receiver typically activates the matching evidence item.
+   */
+  onHighlightClicked?(annotationId: string): void;
+  /**
+   * When true, paint the PDF text-layer spans in light grey so it's
    * obvious which glyphs have a selectable text overlay and which are
    * image-only. Also logs every onSelection event to the console.
    */
@@ -188,7 +214,19 @@ export interface StoredAnnotation {
  *  - scrolls to `scrollToAnnotationId` if its highlight can be reconstructed
  */
 export function PdfSpikeViewer(props: PdfSpikeViewerProps) {
-  const { pdfUrl, storedAnnotations, onSelectionCaptured, scrollToAnnotationId, debugTextLayer } = props;
+  const {
+    pdfUrl,
+    storedAnnotations,
+    onSelectionCaptured,
+    scrollToAnnotationId,
+    activeAnnotationId,
+    onHighlightClicked,
+    debugTextLayer,
+  } = props;
+  const HighlightContainer = useMemo(
+    () => makeSpikeHighlightContainer({ activeAnnotationId, onHighlightClicked }),
+    [activeAnnotationId, onHighlightClicked],
+  );
   const utilsRef = useRef<PdfHighlighterUtils | null>(null);
   const [didScroll, setDidScroll] = useState<string | null>(null);
 
@@ -261,7 +299,7 @@ export function PdfSpikeViewer(props: PdfSpikeViewerProps) {
               onSelectionCaptured(capture, selectors);
             }}
           >
-            <SpikeHighlightContainer />
+            <HighlightContainer />
           </PdfHighlighter>
         )}
       </PdfLoader>