Implement CE-WP-0002 T03-T09: ingest, anchor resolution, engine, UI, persistence, e2e

Completes the PDF review slice end-to-end. After this commit a user can
open a fixture, select text, save an evidence item with commentary, see
it in the sidebar, reload the page, click the item, and the viewer
scrolls to the passage.

- T03 src/source/pdf/{fingerprint,extract,ingest}.ts + 39 fixture tests
  - SHA-256 fingerprint over a fresh ArrayBuffer (TS BufferSource-safe)
  - PDF.js text extract; per-page normalize then join with "\n\n"
  - PageMap + OffsetMap (gap-free coverage); pageLength = end - start
  - Updated manifest's Betriebskosten quote to one PDF.js extracts cleanly
- T04 src/anchor/selectors/{create,resolve}.ts + 25 unit + 7 fixture tests
  - createSelectors emits the maximal redundant set (TextQuote +
    TextPosition + PdfRect + PdfPageText when available)
  - resolveSelectors implements the SharedContracts §7 ladder; confidence
    1.0 (pos+quote) → 0.7 (rect-only) → 0 (unresolved)
  - Cross-module integration test moved to tests/integration/ to honor
    the anchor↛source boundary lint rule
- T05 engine: sync event bus over the closed §4 vocabulary, Map-backed
  repos, services, createEngine() composition root, 12 tests
- T06 work + app: three-pane shell (CollectionList | ViewerShell |
  EvidenceSidebar) wired through EngineProvider; EngineContext lives in
  src/work/ to respect the work↛app boundary; SpikeApp deleted
- T07 AnnotationToolbar: pendingSelection in context; Save runs
  createSelectors → engine.annotations.create → engine.evidence.create
- T08 click-to-reopen + localStorage persistence
  - scrollToAnnotation state in context with a version counter so a
    second click on the same item re-fires the viewer scroll
  - captureSnapshot/restoreSnapshot/attachPersister/restoreFromStorage;
    restore bypasses services to avoid event-loops
  - active-document id persisted alongside the snapshot so reload lands
    on the same fixture; ADR-0005 written
  - 9 persistence tests
- T09 tests/integration/app-prd-scenario.dom.test.tsx
  - end-to-end happy-dom test of PRD scenario steps 1-8 through the real
    React tree; viewer + ingest mocked per ADR-0004's headless-Chromium
    limitation. Fixed memo-deps bug in EvidenceSidebar/ViewerShell where
    useEngineEventTick values were not included in the useMemo deps,
    leaving stale memoization across event-driven re-renders
- vitest.config.ts: happy-dom for *.dom.test.{ts,tsx} files
- noEmit added to tsconfig so tsc -b doesn't litter src/ with .js outputs

Gates: typecheck ✓ lint ✓ test 109/109 across 11 files ✓ build ✓

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

src/work/AnnotationToolbar.tsx

@@ -0,0 +1,100 @@
+/**
+ * AnnotationToolbar — wires "I selected text" into "evidence appears in
+ * the sidebar".
+ *
+ * Visible only when a `pendingSelection` is set (the viewer publishes
+ * captures into context, then this toolbar lets the user attach commentary
+ * and commit). On Save it runs the full pipeline:
+ *
+ *   1. `createSelectors(capture, representation)` — anchor builds the
+ *      maximal selector set against the active representation.
+ *   2. `engine.annotations.create(...)` — engine mints an Annotation +
+ *      emits AnnotationCreated.
+ *   3. `engine.evidence.create(...)` — engine mints the EvidenceItem with
+ *      the user's commentary, emits EvidenceItemCreated.
+ *
+ * The sidebar re-renders via the engine event bus, so no other glue is
+ * needed.
+ */
+
+import { useEffect, useState } from "react";
+import { createSelectors } from "@anchor/index";
+import {
+  useActiveDocument,
+  useEngine,
+  usePendingSelection,
+} from "./EngineContext";
+
+export function AnnotationToolbar() {
+  const engine = useEngine();
+  const { document, representation } = useActiveDocument();
+  const { pending, set } = usePendingSelection();
+  const [commentary, setCommentary] = useState("");
+
+  // Reset the commentary box whenever a fresh selection arrives.
+  useEffect(() => {
+    setCommentary("");
+  }, [pending]);
+
+  if (!pending || !document || !representation) return null;
+
+  const handleSave = () => {
+    const selectors = createSelectors(pending.capture, representation);
+    const annotation = engine.annotations.create({
+      documentId: document.id,
+      representationId: representation.id,
+      selectors,
+      quote: pending.capture.text,
+    });
+    engine.evidence.create({
+      annotationIds: [annotation.id],
+      ...(commentary.trim().length > 0 ? { commentary: commentary.trim() } : {}),
+    });
+    set(null);
+  };
+
+  const handleDiscard = () => set(null);
+
+  const quote = pending.capture.text;
+  const shortQuote = quote.length > 200 ? `${quote.slice(0, 200)}…` : quote;
+
+  return (
+    <div
+      style={{
+        borderBottom: "1px solid #f0c040",
+        background: "#fff8d6",
+        padding: 8,
+        fontFamily: "system-ui, sans-serif",
+        fontSize: 12,
+      }}
+    >
+      <div style={{ marginBottom: 6, fontWeight: 600 }}>
+        New annotation ({pending.selectors.length} selector{pending.selectors.length === 1 ? "" : "s"})
+      </div>
+      <div style={{ marginBottom: 6, fontStyle: "italic", color: "#444" }}>
+        &ldquo;{shortQuote}&rdquo;
+      </div>
+      <textarea
+        value={commentary}
+        onChange={(e) => setCommentary(e.target.value)}
+        placeholder="Add a one-line comment (optional)…"
+        rows={2}
+        style={{
+          width: "100%",
+          boxSizing: "border-box",
+          fontSize: 12,
+          padding: 4,
+          marginBottom: 6,
+        }}
+      />
+      <div style={{ display: "flex", gap: 6 }}>
+        <button onClick={handleSave} style={{ fontSize: 12, padding: "4px 10px" }}>
+          Save evidence
+        </button>
+        <button onClick={handleDiscard} style={{ fontSize: 12, padding: "4px 10px" }}>
+          Discard
+        </button>
+      </div>
+    </div>
+  );
+}