Implement EANCH-WP-0002 and EANCH-WP-0003 anchor hardening and DOM selectors

WP-0002: stale vs unresolved resolution, orphaned flag/helper, bounded
fuzzy quote recovery, and PdfViewerAdapter promotion with resolveSelectors
integration. WP-0003: DomSelectionCapture, DOM create/resolve ladder,
HtmlViewerAdapter under evidence-anchor/dom, and finished workplans.

Verification: 42 anchor tests, citation-evidence typecheck + 51 tests green.

src/selectors/resolve.dom.test.ts

@@ -0,0 +1,77 @@
+import { describe, expect, it } from "vitest";
+import type { DocumentRepresentation } from "@citation-evidence/engine/shared";
+import type { DocumentId, RepresentationId } from "@citation-evidence/engine/shared";
+import type { Selector } from "@citation-evidence/engine/shared";
+import { resolveSelectors } from "./resolve";
+
+const blockText = "The quick brown fox jumps over the lazy dog.";
+const text = `## Section\n\n${blockText}`;
+
+function repr(structureStart = text.indexOf(blockText)): DocumentRepresentation {
+  return {
+    id: "rep_dom" as RepresentationId,
+    documentId: "doc_dom" as DocumentId,
+    representationType: "markdown-rendered",
+    contentHash: "test",
+    canonicalText: text,
+    structureMap: [
+      {
+        globalStart: structureStart,
+        globalEnd: structureStart + blockText.length,
+        path: [{ kind: "section", index: 0, label: "Section" }],
+        containerPath: [0, 1, 0],
+      },
+    ],
+    generatedAt: "2026-07-09T00:00:00.000Z",
+  };
+}
+
+describe("resolveSelectors (dom)", () => {
+  it("resolves DomRangeSelector via structureMap", () => {
+    const foxStart = text.indexOf("brown fox");
+    const selectors: Selector[] = [
+      {
+        type: "DomRangeSelector",
+        startPath: [0, 1, 0],
+        startOffset: foxStart - text.indexOf(blockText),
+        endPath: [0, 1, 0],
+        endOffset: foxStart - text.indexOf(blockText) + "brown fox".length,
+      },
+    ];
+    const r = resolveSelectors(selectors, repr());
+    expect(r.status).toBe("resolved");
+    expect(r.confidence).toBe(0.75);
+    expect(r.candidates[0]?.textPosition?.start).toBe(foxStart);
+  });
+
+  it("resolves StructuralSelector when offsets shift within the block", () => {
+    const shifted = "The quick brown fox jumps over a sleepy dog.";
+    const shiftedDoc = `## Section\n\n${shifted}`;
+    const blockStart = shiftedDoc.indexOf(shifted);
+    const selectors: Selector[] = [
+      {
+        type: "StructuralSelector",
+        path: [{ kind: "section", index: 0, label: "Section" }],
+        startOffset: blockText.indexOf("brown fox"),
+        endOffset: blockText.indexOf("brown fox") + "brown fox".length,
+      },
+    ];
+    const representation: DocumentRepresentation = {
+      ...repr(blockStart),
+      canonicalText: shiftedDoc,
+      structureMap: [
+        {
+          globalStart: blockStart,
+          globalEnd: blockStart + shifted.length,
+          path: [{ kind: "section", index: 0, label: "Section" }],
+        },
+      ],
+    };
+    const r = resolveSelectors(selectors, representation);
+    expect(r.status).toBe("resolved");
+    expect(r.confidence).toBe(0.65);
+    expect(r.candidates[0]?.textPosition?.start).toBe(
+      representation.canonicalText!.indexOf("brown fox"),
+    );
+  });
+});