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/engine/services/documents.ts

@@ -0,0 +1,63 @@
+/**
+ * Document service — registers ingested documents and emits the §4 events.
+ *
+ * The ingest pipeline (`src/source/pdf/ingest.ts`) is a pure function over
+ * bytes — it does not touch the engine. The app composition root calls
+ * `ingestPdf` then hands the result to `documentService.register()`, which
+ * is where the engine takes over: persist into the repos, emit
+ * `DocumentImported` + `DocumentRepresentationGenerated`.
+ */
+
+import type { Document, DocumentRepresentation } from "@shared/document";
+import type { DocumentId, RepresentationId } from "@shared/ids";
+
+import type { EventBus } from "../events";
+import type { DocumentRepository, RepresentationRepository } from "../repos";
+
+export interface DocumentService {
+  register(input: {
+    readonly document: Document;
+    readonly representation: DocumentRepresentation;
+  }): { readonly document: Document; readonly representation: DocumentRepresentation };
+  get(id: DocumentId): Document | null;
+  list(): readonly Document[];
+  getRepresentation(id: RepresentationId): DocumentRepresentation | null;
+  listRepresentations(documentId: DocumentId): readonly DocumentRepresentation[];
+}
+
+export function createDocumentService(
+  documents: DocumentRepository,
+  representations: RepresentationRepository,
+  bus: EventBus,
+): DocumentService {
+  return {
+    register({ document, representation }) {
+      const storedDocument = documents.create(document);
+      const storedRepresentation = representations.create(representation);
+      bus.emit({
+        type: "DocumentImported",
+        documentId: storedDocument.id,
+        document: storedDocument,
+      });
+      bus.emit({
+        type: "DocumentRepresentationGenerated",
+        documentId: storedDocument.id,
+        representationId: storedRepresentation.id,
+        representation: storedRepresentation,
+      });
+      return { document: storedDocument, representation: storedRepresentation };
+    },
+    get(id) {
+      return documents.get(id);
+    },
+    list() {
+      return documents.list();
+    },
+    getRepresentation(id) {
+      return representations.get(id);
+    },
+    listRepresentations(documentId) {
+      return representations.listByDocument(documentId);
+    },
+  };
+}