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/highlight-styles.css

@@ -0,0 +1,38 @@
+/*
+ * Evidence highlight styling — matches the sidebar's "evidence card"
+ * palette so the viewer and the sidebar speak the same visual language.
+ *
+ *   .TextHighlight__part            inactive highlight (light yellow fill,
+ *                                   thin amber border)
+ *   .TextHighlight--active …        the currently-focused evidence — same
+ *                                   fill, thicker border
+ *
+ * The "active" class is applied by the spike viewer when the parent
+ * wrapper is marked with `data-ce-active="true"` so a single
+ * `activeAnnotationId` prop drives the entire viewer's focus state
+ * without per-highlight component coupling.
+ *
+ * We override the library's red `--scrolledTo` box-shadow so an
+ * activation doesn't flash a red ring that doesn't match the palette.
+ */
+
+.TextHighlight__part {
+  background: #fff8d6 !important;
+  outline: 1px solid #e0c050 !important;
+  outline-offset: 0;
+  cursor: pointer;
+  transition: outline 0.15s ease;
+}
+
+[data-ce-active="true"] .TextHighlight__part {
+  outline: 3px solid #b78b1c !important;
+  background: #fff5b8 !important;
+}
+
+/* The library applies `--scrolledTo` after a programmatic scroll. We
+   override its red box-shadow so the "you just landed on this" cue
+   sticks with the yellow palette. The thicker border from
+   `data-ce-active` already conveys focus. */
+.TextHighlight--scrolledTo .TextHighlight__part {
+  box-shadow: none !important;
+}