feat(web): write descriptions and comments with a visual editor

ts-rich-editor (TipTap) shows the formatting while writing: bold,
italic, strike, code, headings, lists, task lists, quotes, code blocks
and links, with @ suggesting the project's members and pasted
screenshots uploaded as attachments. It reads and writes the same
Markdown the API keeps (mentions as @[Name](id), images as
attachment:<id>, tables too), so nothing already written changes.

Used for comments, replies, editing a comment or a description, a new
ticket from the board and the public proposal form; the Markdown hint
and the paste directive are gone. List markers sat on a line of their
own, and task lists showed a stray bullet, in the editor and when read.

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

libs/web/tracker/presenters/src/lib/ui/rich-text.spec.ts

@@ -0,0 +1,88 @@
+import { Editor } from '@tiptap/core';
+import { markdownOf, richTextExtensions } from './rich-text';
+
+/** Markdown in, the editor's Markdown out: what an edit that changes nothing saves. */
+function roundTrip(markdown: string): string {
+  const editor = new Editor({
+    element: document.createElement('div'),
+    extensions: richTextExtensions(),
+    content: markdown,
+    contentType: 'markdown',
+  });
+  const out = markdownOf(editor);
+  editor.destroy();
+  return out;
+}
+
+describe('rich text', () => {
+  it('keeps mentions as the API reads them', () => {
+    expect(roundTrip('Hola @[Ana López](101), ¿lo miras?')).toBe(
+      'Hola @[Ana López](101), ¿lo miras?',
+    );
+  });
+
+  it('keeps pasted images pointing at their attachment', () => {
+    expect(roundTrip('Mira:\n\n![captura.png](attachment:abc-123)')).toContain(
+      '![captura.png](attachment:abc-123)',
+    );
+  });
+
+  it('keeps formatting, lists, task lists, quotes, code and links', () => {
+    const text = [
+      '## Pasos',
+      '',
+      'Texto con **negrita**, *cursiva*, ~~tachado~~ y `código`.',
+      '',
+      '- uno',
+      '- dos',
+      '',
+      '1. primero',
+      '2. segundo',
+      '',
+      '- [ ] pendiente',
+      '- [x] hecho',
+      '',
+      '> una cita',
+      '',
+      '```',
+      'const a = 1;',
+      '```',
+      '',
+      '[enlace](https://example.com)',
+    ].join('\n');
+    const out = roundTrip(text);
+    for (const piece of [
+      '## Pasos',
+      '**negrita**',
+      '*cursiva*',
+      '~~tachado~~',
+      '`código`',
+      '- uno',
+      '1. primero',
+      '- [ ] pendiente',
+      '- [x] hecho',
+      '> una cita',
+      'const a = 1;',
+      '[enlace](https://example.com)',
+    ])
+      expect(out).toContain(piece);
+  });
+
+  it('keeps tables', () => {
+    const out = roundTrip('| a | b |\n| --- | --- |\n| 1 | 2 |');
+    expect(out).toMatch(/\|\s*a\s*\|\s*b\s*\|/);
+    expect(out).toMatch(/\|\s*1\s*\|\s*2\s*\|/);
+  });
+
+  it('answers an empty string for an empty editor', () => {
+    expect(roundTrip('')).toBe('');
+  });
+});
+
+describe('rich text, line breaks', () => {
+  it('keeps a single line break as a line break', () => {
+    const out = roundTrip('primera línea\nsegunda línea');
+    expect(out).not.toBe('primera línea segunda línea');
+    expect(out).toMatch(/primera línea(\s{2}|\\)?\nsegunda línea/);
+  });
+});