Replace markdown editor with native Tiptap editor and add Home navigation

- Migrate renderer from md-editor/md-format to a Tiptap-based native editor
  (native-doc pipeline: native-doc, markdown-to-native, native-to-markdown,
  native-assembly, migration, backup)
- Use pointer-event-based chapter reordering with grab/grabbing cursors to
  avoid the Wayland prohibited-drop cursor while preserving reordering
- Add a persistent Home button that closes the open book and returns to the
  Folio library/welcome screen
- Update app icons, package deps, theme styles, and tests

tests/run-fullbook-test.mjs

@@ -0,0 +1,195 @@
+// Runner for the native Full Book test. Builds a jsdom DOM, bundles the
+// renderer assembly + Tiptap modules, and verifies that a book assembled from
+// native chapters renders with correct chapter order, page-break anchors,
+// reorder behavior, title injection, and Copy-All native fidelity.
+import esbuild from "esbuild";
+import fs from "fs";
+import os from "os";
+import path from "path";
+import url from "url";
+import { JSDOM } from "jsdom";
+
+const dom = new JSDOM("<!DOCTYPE html><html><body></body></html>", {
+  pretendToBeVisual: true,
+  url: "http://localhost/",
+});
+const { window } = dom;
+const g = globalThis;
+g.window = window;
+g.document = window.document;
+g.HTMLElement = window.HTMLElement;
+g.Element = window.Element;
+g.Node = window.Node;
+g.MutationObserver = window.MutationObserver;
+g.getComputedStyle = window.getComputedStyle.bind(window);
+g.DOMParser = window.DOMParser;
+g.requestAnimationFrame = (cb) => setTimeout(cb, 0);
+g.cancelAnimationFrame = (id) => clearTimeout(id);
+
+const out = path.join(os.tmpdir(), `folio-fullbook-${process.pid}.mjs`);
+const entry = path.resolve("tests/.folio-fullbook-test-entry.ts");
+await esbuild.build({
+  entryPoints: [entry],
+  bundle: true,
+  platform: "node",
+  format: "esm",
+  outfile: out,
+  write: true,
+  logLevel: "silent",
+});
+
+const mod = await import(url.pathToFileURL(out).href);
+const {
+  buildFullBookDoc,
+  nativeNodeText,
+  createTiptapEditor,
+  setEditorDoc,
+  getEditorDoc,
+  ChapterBreak,
+  CURRENT_DOC_SCHEMA_VERSION,
+} = mod;
+
+let failures = 0;
+function ok(cond, msg) {
+  if (cond) console.log("  ok -", msg);
+  else {
+    failures++;
+    console.error("FAIL -", msg);
+  }
+}
+
+function findNodes(node, type, acc = []) {
+  if (!node || typeof node !== "object") return acc;
+  if (node.type === type) acc.push(node);
+  for (const c of node.content ?? []) findNodes(c, type, acc);
+  return acc;
+}
+
+// A native chapter doc with a single paragraph of the given text.
+function paraDoc(text) {
+  return {
+    type: "doc",
+    content: [{ type: "paragraph", content: [{ type: "text", text }] }],
+  };
+}
+function headingDoc(text) {
+  return {
+    type: "doc",
+    content: [{ type: "heading", attrs: { level: 1 }, content: [{ type: "text", text }] }],
+  };
+}
+
+function makeFullBookEditor() {
+  const host = window.document.createElement("div");
+  window.document.body.appendChild(host);
+  return createTiptapEditor(host, { onChange: () => undefined }, { editable: false, extensions: [ChapterBreak] });
+}
+
+// --- canonical chapter order / navigation anchors ---
+const chapters = [
+  { id: "c1", title: "One", markdown: "Body one", doc: paraDoc("Body one") },
+  { id: "c2", title: "Two", markdown: "Body two", doc: paraDoc("Body two") },
+  { id: "c3", title: "Three", markdown: "Body three", doc: paraDoc("Body three") },
+];
+const assembled = buildFullBookDoc(chapters);
+ok(assembled.chapterEntries.length === 3, "three chapter entries produced");
+ok(
+  assembled.chapterEntries.map((c) => c.id).join(",") === "c1,c2,c3",
+  "chapter order follows canonical chapterOrder"
+);
+ok(
+  findNodes(assembled.nativeDoc, "chapterBreak").length === 3,
+  "one chapterBreak anchor per chapter"
+);
+ok(
+  findNodes(assembled.nativeDoc, "chapterBreak")[0].attrs.first === true,
+  "first chapter break is marked first"
+);
+ok(
+  findNodes(assembled.nativeDoc, "chapterBreak").slice(1).every((n) => n.attrs.first === false),
+  "subsequent chapter breaks are not first (page breaks)"
+);
+
+// Render into the read-only editor and check DOM anchors in order.
+const editor = makeFullBookEditor();
+setEditorDoc(editor, assembled.nativeDoc);
+const anchors = Array.from(editor.view.dom.querySelectorAll("[data-chapter-id]"));
+ok(anchors.length === 3, "three DOM anchors rendered");
+ok(
+  anchors.map((a) => a.getAttribute("data-chapter-id")).join(",") === "c1,c2,c3",
+  "DOM anchors preserve canonical order"
+);
+ok(anchors[0].classList.contains("first"), "first anchor carries first class");
+ok(
+  anchors.slice(1).every((a) => !a.classList.contains("first")),
+  "subsequent anchors are plain chapter-break separators"
+);
+
+// --- reorder impact on Full Book output ---
+const reordered = buildFullBookDoc([chapters[1], chapters[0], chapters[2]]);
+const reAnchors = Array.from(
+  (() => {
+    const e = makeFullBookEditor();
+    setEditorDoc(e, reordered.nativeDoc);
+    return e.view.dom;
+  })().querySelectorAll("[data-chapter-id]")
+);
+ok(
+  reAnchors.map((a) => a.getAttribute("data-chapter-id")).join(",") === "c2,c1,c3",
+  "reordering chapterOrder reorders Full Book output"
+);
+
+// --- title injection fidelity ---
+const withHeading = buildFullBookDoc([
+  { id: "h1", title: "Title", markdown: "# Title\nrest", doc: headingDoc("Title") },
+]);
+ok(
+  findNodes(withHeading.nativeDoc, "heading").length === 1,
+  "chapter already starting with matching heading is not duplicated"
+);
+const withoutHeading = buildFullBookDoc([
+  { id: "h2", title: "Title", markdown: "body", doc: paraDoc("body") },
+]);
+const heads = findNodes(withoutHeading.nativeDoc, "heading");
+ok(heads.length === 1 && heads[0].attrs.level === 1, "missing title heading is injected as H1");
+ok(
+  nativeNodeText(withoutHeading.nativeDoc).includes("Title"),
+  "injected title text appears in the assembled book"
+);
+
+// --- Copy All native fidelity (round trip) ---
+const copyJson = JSON.stringify(getEditorDoc(editor));
+const parsed = JSON.parse(copyJson);
+const firstDoc = getEditorDoc(editor).doc;
+ok(parsed.schemaVersion === CURRENT_DOC_SCHEMA_VERSION, "copied native doc has schema version");
+ok(
+  findNodes(parsed.doc, "chapterBreak").length === 3,
+  "copied native doc preserves chapterBreak anchors"
+);
+const editor2 = makeFullBookEditor();
+setEditorDoc(editor2, parsed.doc);
+ok(
+  JSON.stringify(getEditorDoc(editor2).doc) === JSON.stringify(firstDoc),
+  "copied native doc reloads byte-identical to editor state"
+);
+ok(
+  nativeNodeText(parsed.doc).includes("Body one") &&
+    nativeNodeText(parsed.doc).includes("Body three"),
+  "copied native content preserves chapter text"
+);
+
+// --- word / char counts ---
+const text = nativeNodeText(assembled.nativeDoc);
+ok(text.includes("Body one") && text.includes("Body three"), "word/char source includes all chapters");
+ok(text.split(/\s+/).filter(Boolean).length >= 3, "word count reflects chapter text");
+
+// --- empty book ---
+const empty = buildFullBookDoc([]);
+ok(
+  empty.nativeDoc.type === "doc" && Array.isArray(empty.nativeDoc.content) && empty.nativeDoc.content.length === 0,
+  "empty book assembles to empty doc"
+);
+
+fs.rmSync(out, { force: true });
+console.log("\nFull Book tests: " + (failures === 0 ? "ALL PASSED" : failures + " FAILED"));
+process.exit(failures === 0 ? 0 : 1);