fix: a title-page master governs one page, not the whole document

An ODF master page whose style:next-style-name names another master applies
to a single page. Read as the section's running header, this file's full-page
title background repeated on every page and its height pushed each block onto
its own — 276 pages instead of 16.

Its zones now become the first-page variants, the successor's the running
ones, and a positioned frame in a zone is dropped as in DOCX.

src/lib/import/CLAUDE.md

@@ -23,7 +23,7 @@ The **Open .odt** button (`App.svelte`) parses an uploaded file with `importOdt(
 
 ## Header/footer import
 
-- **Import:** `StyleResolver.masterPageHF()` reads `style:header`/`style:footer` + the header/footer-style heights; `pageGeometry()` reconstructs the body margin (page margin + zone height + spacing) and `edgeDistancesCm()` returns the raw page margins as the zone distances. The header↔body spacing is only reserved when `style:dynamic-spacing="false"` — a `true` (LibreOffice's usual) means the gap collapses, so reserving it would shove the body down. `convertHfZone` → single-paragraph doc (extra paragraphs → hard breaks; a text-less zone that carries a background/border rule line is kept, box props merged with the bottom rule from the last paragraph); `convertInline(…, hfFields=true)` keeps `text:page-number`/`-count` as field nodes. Per-page variants (`header-first`/`-left`) are ignored with a warning. `hfIsEmpty` counts a rule-/shading-only paragraph as non-empty so it renders and exports.
+- **Import:** `StyleResolver.masterPageHF()` reads `style:header`/`style:footer` + the header/footer-style heights; `pageGeometry()` reconstructs the body margin (page margin + zone height + spacing) and `edgeDistancesCm()` returns the raw page margins as the zone distances. The header↔body spacing is only reserved when `style:dynamic-spacing="false"` — a `true` (LibreOffice's usual) means the gap collapses, so reserving it would shove the body down. `convertHfZone` → single-paragraph doc (extra paragraphs → hard breaks; a text-less zone that carries a background/border rule line is kept, box props merged with the bottom rule from the last paragraph); `convertInline(…, hfFields=true)` keeps `text:page-number`/`-count` as field nodes. A master page whose `style:next-style-name` points at *another* master governs one page only (the "different first page" idiom): its own zones become the first-page variants and the successor's the running ones — read as the running header instead, a title-page master repeats on every page of its section and its height pushes each block onto its own page. As in DOCX, a zone's positioned (non-`as-char`) frames are dropped with a warning: the one-paragraph zone can't place them, and a page-sized background reserves the whole page inline. `hfIsEmpty` counts a rule-/shading-only paragraph as non-empty so it renders and exports.
 
 ## Defaults on DOCX import
 

src/lib/import/odt.ts

@@ -1428,11 +1428,14 @@ function convertInline(root: Element, ctx: Ctx, baseProps: PropMap, defaults: Bl
       }
       if (e.namespaceURI === NS.draw) {
         const conv = convertDrawElement(e, ctx);
-        // The one-paragraph header/footer schema holds inline images (forced
-        // as-character) but not boxes — those are dropped with a warning.
+        // The one-paragraph zone takes as-char images only — boxes and positioned
+        // frames (a page-sized background reserves the whole page inline) are dropped
+        // with a warning, as the DOCX importer does.
         if (hfFields) {
-          if (conv?.inline?.type === 'image') out.push({ ...conv.inline, attrs: { ...conv.inline.attrs, wrap: 'inline' } });
-          else if (conv) ctx.warnings.add('Drawings were removed');
+          const wrap = conv?.inline?.attrs?.wrap;
+          if (conv?.inline?.type === 'image' && (!wrap || wrap === 'inline')) {
+            out.push({ ...conv.inline, attrs: { ...conv.inline.attrs, wrap: 'inline' } });
+          } else if (conv) ctx.warnings.add('Drawings were removed');
           continue;
         }
         if (conv?.inline) out.push(conv.inline);

src/lib/import/styleResolver.ts

@@ -518,22 +518,27 @@ export class StyleResolver {
     const mp = this.masterPageEl(pageName);
     const layout = this.pageLayoutEl();
 
-    const zone = (local: string): Element | null => {
-      if (!mp) return null;
-      for (const child of Array.from(mp.children)) {
-        if (child.namespaceURI === NS.style && child.localName === local) return child;
-      }
-      return null;
-    };
-    // header-first/footer-first (ODF 1.3 style: or older LibreOffice loext:) — match
-    // by local name in either namespace so both producers round-trip.
-    const firstZone = (local: string): Element | null => {
-      if (!mp) return null;
-      for (const child of Array.from(mp.children)) {
+    // Match by local name in either namespace: header-first/footer-first are ODF 1.3
+    // style: or older LibreOffice loext:, so both producers round-trip.
+    const zoneIn = (owner: Element | null, local: string): Element | null => {
+      if (!owner) return null;
+      for (const child of Array.from(owner.children)) {
         if (child.localName === local && (child.namespaceURI === NS.style || child.namespaceURI === NS.loext)) return child;
       }
       return null;
     };
+    // A master page naming a different style:next-style-name governs one page and then
+    // hands over — the "different first page" idiom. Its own zones become the first-page
+    // variants, the successor's the ones every later page in the section uses.
+    const nextName = mp?.getAttributeNS(NS.style, 'next-style-name') ?? null;
+    const successor = nextName && nextName !== mp?.getAttributeNS(NS.style, 'name')
+      ? this.masterPageEl(nextName)
+      : null;
+    const rest = successor ?? mp;
+
+    const zone = (local: string) => zoneIn(rest, local);
+    const firstZone = (local: string): Element | null =>
+      zoneIn(mp, `${local}-first`) ?? (successor ? zoneIn(mp, local) : null);
     const extraCm = (local: 'header-style' | 'footer-style', spacingAttr: 'margin-bottom' | 'margin-top'): number => {
       if (!layout) return 0;
       let props: Element | null = null;
@@ -558,11 +563,11 @@ export class StyleResolver {
     return {
       header: zone('header'),
       footer: zone('footer'),
-      headerFirst: firstZone('header-first'),
-      footerFirst: firstZone('footer-first'),
+      headerFirst: firstZone('header'),
+      footerFirst: firstZone('footer'),
       // Even-page variant (Word odd/even). ODF header-left = the left (even) page.
-      headerLeft: firstZone('header-left'),
-      footerLeft: firstZone('footer-left'),
+      headerLeft: zoneIn(rest, 'header-left'),
+      footerLeft: zoneIn(rest, 'footer-left'),
       headerExtraCm: extraCm('header-style', 'margin-bottom'),
       footerExtraCm: extraCm('footer-style', 'margin-top'),
     };