feat(workspace): numbered lists and reliable markdown paste

- block type 'numbered' (/number): 1., a., i. by nesting, continues on
  Enter, an empty item ends the list; markdown export/import as 1.
- pasting: parser moved to lib/pasteOutline with tests; blank lines split
  paragraphs, numbered lists keep their type, indentation levels follow
  the widths in use (2, 3 or 4 spaces, tabs)
- text that stays in the focused block after pasting (a paragraph with
  line breaks) was dropped; the block now takes it

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/lib/__tests__/outlineList.test.ts

@@ -0,0 +1,27 @@
+import { describe, it, expect } from 'vitest';
+import { listLabel, numberedLabels } from '../outlineList';
+import type { DocumentBlock } from '../types';
+
+const blk = (id: string, level: number, type: DocumentBlock['type'] = 'numbered'): DocumentBlock => ({
+  id, documentId: 'd', type, content: id, level, position: 0,
+});
+
+describe('numbered lists', () => {
+  it('formats numbers, letters and roman numerals by depth', () => {
+    expect(listLabel(3, 0)).toBe('3.');
+    expect(listLabel(2, 1)).toBe('b.');
+    expect(listLabel(27, 1)).toBe('aa.');
+    expect(listLabel(4, 2)).toBe('iv.');
+    expect(listLabel(1, 3)).toBe('1.');
+  });
+
+  it('counts siblings, nests and restarts after other blocks', () => {
+    const labels = numberedLabels([
+      blk('a', 0), blk('a1', 1), blk('a2', 1), blk('a2i', 2), blk('b', 0),
+      blk('note', 0, 'text'), blk('c', 0), blk('plain', 1, 'text'), blk('c1', 2),
+    ]);
+    expect(Object.fromEntries(labels)).toEqual({
+      a: '1.', a1: 'a.', a2: 'b.', a2i: 'i.', b: '2.', c: '1.', c1: 'a.',
+    });
+  });
+});

frontend/src/lib/__tests__/pasteOutline.test.ts

@@ -0,0 +1,38 @@
+import { describe, it, expect } from 'vitest';
+import { parsePastedLines } from '../pasteOutline';
+
+const parse = (text: string) => parsePastedLines(text.split('\n'));
+
+describe('parsePastedLines', () => {
+  it('splits paragraphs at blank lines and keeps wrapped lines together', () => {
+    expect(parse('Erster Absatz\nnoch erster\n\nZweiter Absatz')).toEqual([
+      { type: 'text', content: 'Erster Absatz\nnoch erster', indent: 0 },
+      { type: 'text', content: 'Zweiter Absatz', indent: 0 },
+    ]);
+  });
+
+  it('keeps numbered lists with nesting (3-space indent)', () => {
+    expect(parse('1. Eins\n   1. Unterpunkt\n      1. Tiefer\n2. Zwei')).toEqual([
+      { type: 'numbered', content: 'Eins', indent: 0 },
+      { type: 'numbered', content: 'Unterpunkt', indent: 1 },
+      { type: 'numbered', content: 'Tiefer', indent: 2 },
+      { type: 'numbered', content: 'Zwei', indent: 0 },
+    ]);
+  });
+
+  it('reads headings, todos, bullets and dividers', () => {
+    expect(parse('# Titel\nText danach\n- [x] erledigt\n- Punkt\n---')).toEqual([
+      { type: 'h1', content: 'Titel', indent: 0 },
+      { type: 'text', content: 'Text danach', indent: 0 },
+      { type: 'todo', checked: true, content: 'erledigt', indent: 0 },
+      { type: 'text', content: 'Punkt', indent: 0 },
+      { type: 'divider', content: '---', indent: 0 },
+    ]);
+  });
+
+  it('keeps fenced code as one block', () => {
+    const items = parse('```go\nfunc main() {}\n\n```\nDanach');
+    expect(items[0].content).toBe('```go\nfunc main() {}\n\n```');
+    expect(items[1]).toEqual({ type: 'text', content: 'Danach', indent: 0 });
+  });
+});

frontend/src/lib/outlineList.ts

@@ -0,0 +1,65 @@
+import type { DocumentBlock } from './types';
+
+// Numbered lists in the outliner: consecutive 'numbered' siblings count 1, 2, 3 …; a numbered list
+// inside another one uses a, b, c, the next level i, ii, iii, then numbers again.
+
+function alpha(n: number): string {
+  let s = '';
+  while (n > 0) {
+    n--;
+    s = String.fromCharCode(97 + (n % 26)) + s;
+    n = Math.floor(n / 26);
+  }
+  return s;
+}
+
+const ROMAN: [number, string][] = [
+  [1000, 'm'], [900, 'cm'], [500, 'd'], [400, 'cd'], [100, 'c'], [90, 'xc'],
+  [50, 'l'], [40, 'xl'], [10, 'x'], [9, 'ix'], [5, 'v'], [4, 'iv'], [1, 'i'],
+];
+
+function roman(n: number): string {
+  let s = '';
+  for (const [v, r] of ROMAN) {
+    while (n >= v) {
+      s += r;
+      n -= v;
+    }
+  }
+  return s;
+}
+
+export function listLabel(n: number, depth: number): string {
+  switch (depth % 3) {
+    case 1:
+      return `${alpha(n)}.`;
+    case 2:
+      return `${roman(n)}.`;
+    default:
+      return `${n}.`;
+  }
+}
+
+/** Label ("1.", "b.", "iii.") for every numbered block, in document order. */
+export function numberedLabels(blocks: DocumentBlock[]): Map<string, string> {
+  const labels = new Map<string, string>();
+  const runs = new Map<number, number>(); // level -> count of the current run
+  const chain: DocumentBlock[] = []; // last block seen per level = ancestors of the next one
+  for (const b of blocks) {
+    const level = Math.max(0, b.level || 0);
+    for (const l of Array.from(runs.keys())) {
+      if (l > level) runs.delete(l);
+    }
+    chain.length = Math.min(chain.length, level);
+    if (b.type === 'numbered') {
+      const n = (runs.get(level) ?? 0) + 1;
+      runs.set(level, n);
+      const depth = chain.filter((a) => a && a.type === 'numbered').length;
+      labels.set(b.id, listLabel(n, depth));
+    } else {
+      runs.delete(level);
+    }
+    chain[level] = b;
+  }
+  return labels;
+}

frontend/src/lib/pasteOutline.ts

@@ -0,0 +1,109 @@
+import type { BlockType } from './types';
+
+// Turns pasted (Markdown) text into outline items: headings, todos, bullets, numbered items, dividers,
+// fenced code and paragraphs. A blank line ends a paragraph; indentation becomes the nesting level.
+
+export interface PastedItem {
+  type: BlockType;
+  checked?: boolean;
+  content: string;
+  indent: number;
+}
+
+function leadingWidth(line: string): { width: number; rest: string } {
+  let width = 0;
+  let i = 0;
+  while (i < line.length && (line[i] === ' ' || line[i] === '\t')) {
+    width += line[i] === '\t' ? 4 : 1;
+    i++;
+  }
+  return { width, rest: line.slice(i) };
+}
+
+export function parsePastedLines(rawLines: string[]): PastedItem[] {
+  // Indentation steps differ (2, 3 or 4 spaces, tabs): the distinct widths in use are the levels
+  const widths = Array.from(
+    new Set(rawLines.filter((l) => l.trim() !== '').map((l) => leadingWidth(l).width))
+  ).sort((a, b) => a - b);
+  const levelOf = (w: number) => Math.max(0, widths.indexOf(w));
+
+  const items: PastedItem[] = [];
+  let current: PastedItem | null = null;
+  let inCode = false;
+  let afterHeading = false;
+
+  const flush = () => {
+    if (current) {
+      current.content = current.content.trimEnd();
+      items.push(current);
+      current = null;
+    }
+  };
+
+  for (const rawLine of rawLines) {
+    if (inCode) {
+      if (current) (current as PastedItem).content += '\n' + rawLine;
+      if (rawLine.trim().startsWith('```')) {
+        inCode = false;
+        flush();
+      }
+      continue;
+    }
+    if (rawLine.trim().startsWith('```')) {
+      inCode = true;
+      flush();
+      current = { type: 'text', content: rawLine, indent: 0 };
+      afterHeading = false;
+      continue;
+    }
+
+    const { width, rest } = leadingWidth(rawLine);
+    const indent = levelOf(width);
+    const line = rest.trimEnd();
+
+    // A blank line ends the paragraph or list item
+    if (line === '') {
+      flush();
+      continue;
+    }
+
+    const heading = line.match(/^(#{1,3})\s+(.*)$/);
+    if (heading) {
+      flush();
+      afterHeading = true;
+      items.push({ type: (['h1', 'h2', 'h3'] as const)[heading[1].length - 1], content: heading[2], indent });
+      continue;
+    }
+    if (/^(?:-{3,}|\*{3,}|_{3,})$/.test(line)) {
+      flush();
+      afterHeading = false;
+      items.push({ type: 'divider', content: '---', indent });
+      continue;
+    }
+
+    const todo = line.match(/^[-*+]\s*\[([ xX])\]\s*(.*)$/);
+    const bullet = line.match(/^[-*+•]\s+(.*)$/);
+    const numbered = line.match(/^\d+[.)]\s+(.*)$/);
+    if (todo || bullet || numbered) {
+      flush();
+      afterHeading = false;
+      current = todo
+        ? { type: 'todo', checked: todo[1].toLowerCase() === 'x', content: todo[2], indent }
+        : numbered
+        ? { type: 'numbered', content: numbered[1], indent }
+        : { type: 'text', content: bullet![1], indent };
+      continue;
+    }
+
+    // Plain text: continues the paragraph or list item above (a wrapped line), else starts a paragraph
+    if (current && !afterHeading) {
+      (current as PastedItem).content += '\n' + line;
+    } else {
+      flush();
+      current = { type: 'text', content: line, indent };
+    }
+    afterHeading = false;
+  }
+  flush();
+  return items;
+}

frontend/src/lib/types.ts

@@ -261,7 +261,7 @@ export const DATA_SECTIONS: { id: DataSection; label: string }[] = [
   { id: 'themes', label: 'Themes' },
 ];
 
-export type BlockType = 'h1' | 'h2' | 'h3' | 'paragraph' | 'text' | 'todo' | 'bullet' | 'code' | 'callout' | 'divider' | 'table' | 'progress' | 'image' | 'audio';
+export type BlockType = 'h1' | 'h2' | 'h3' | 'paragraph' | 'text' | 'todo' | 'bullet' | 'numbered' | 'code' | 'callout' | 'divider' | 'table' | 'progress' | 'image' | 'audio';
 
 export interface DocumentBlock {
   id: string;