fix: a frame behind the text can be picked again

The browser hit-tests a behind-text frame last of all — the page and every
paragraph over it come first — so a cover picture could not be clicked at all:
the caret landed in the text as if it were not there. A mousedown over one now
goes to the frame's own node view, which selects and drags it as any other
frame; text painted over the point still wins, as the caret does in both
products. A box's node view mirrors renderHTML's data-wrap for it, as an
image's already did.

Claude-Session: https://claude.ai/code/session_01Wzs2qG6Y5qm7mKmJHfu44G

tests/normalize.ts

@@ -13,6 +13,7 @@ const ORDERED_DEFAULTS: Record<string, unknown> = {
   joinPrev: false, // pageBreaks.ts's split marker; the export merges the halves
   marginLeft: 0, marginRight: 0, marginTop: 0, marginBottom: 0, // a table's, once a command has touched them
   alt: '', inFront: false, paddingCm: 0.15, flipV: false, textVertical: false, // the editor's own picture and box defaults
+  wrapFromPage: false,
   // index attrs the DOCX TOC field has no switch for come back at their defaults
   maxLevel: MAX_HEADING_LEVEL, leader: '.', citationStyle: 'key',
 };

tests/unit/frame-page-relative.test.ts

@@ -0,0 +1,41 @@
+// A frame whose vertical offset counts from the page the anchor lands on (Word's
+// positionV relativeFrom="page", ODF's style:vertical-rel="page") keeps that relation
+// through both formats — read as paragraph-relative it would move on every re-open.
+import { describe, it, expect } from 'vitest';
+import { buildOdt } from '../../src/lib/export/odt';
+import { importOdt } from '../../src/lib/import/odt';
+import { buildDocx } from '../../src/lib/export/docx';
+import { importDocx } from '../../src/lib/import/docx';
+
+type N = any;
+
+const PNG = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAIAAAD91JpzAAAAD0lEQVR4nGNgYPgPRmAKABf2A/1+6zfzAAAAAElFTkSuQmCC';
+
+const doc: N = { type: 'doc', content: [
+  { type: 'paragraph', content: [
+    { type: 'image', attrs: { src: PNG, width: 200, height: 100, wrap: 'through', wrapOffset: 1, wrapOffsetY: 17.6, wrapFromPage: true } },
+    { type: 'textBox', attrs: { width: 300, height: 120, wrap: 'through', wrapOffset: 0, wrapOffsetY: 5.5, wrapFromPage: true, fillColor: '#34ABA2' },
+      content: [{ type: 'paragraph' }] },
+  ] },
+  { type: 'paragraph', content: [{ type: 'text', text: 'Body' }] },
+] };
+
+const find = (n: N, type: string): N => {
+  if (n.type === type) return n;
+  for (const c of n.content ?? []) { const hit = find(c, type); if (hit) return hit; }
+  return null;
+};
+
+describe('a frame placed against the page', () => {
+  it('round-trips through ODF', async () => {
+    const back = importOdt(await buildOdt(doc)).content as N;
+    expect(find(back, 'image').attrs).toMatchObject({ wrapFromPage: true, wrapOffsetY: 17.6 });
+    expect(find(back, 'textBox').attrs).toMatchObject({ wrapFromPage: true, wrapOffsetY: 5.5 });
+  });
+
+  it('round-trips through DOCX', async () => {
+    const back = importDocx(await buildDocx(doc)).content as N;
+    expect(find(back, 'image').attrs).toMatchObject({ wrapFromPage: true, wrapOffsetY: 17.6 });
+    expect(find(back, 'textBox').attrs).toMatchObject({ wrapFromPage: true, wrapOffsetY: 5.5 });
+  });
+});