fix: direct formatting on a run beats its named character style

A character style is a stylesheet rule, direct formatting an inline style on the
run's span. The charStyle mark ranked below TextStyle, so its span sat *inside*
and the rule won over the ancestor's inline style — a 9pt style silently undid a
run's own 10pt. Priority 102 lifts it above TextStyle's 101.

One fixture: 259 → 172 parity issues, lineEnd 49 → 7.

tests/unit/mark-order.test.ts

@@ -0,0 +1,18 @@
+import { describe, it, expect } from 'vitest';
+import { getSchema, generateHTML } from '@tiptap/core';
+import { extensions } from '../../src/lib/editor/extensions';
+
+// A named character style renders as a stylesheet rule, direct formatting as an inline
+// style — so the charStyle span has to sit outside, or the rule beats the ancestor.
+describe('mark nesting', () => {
+  it('puts charStyle outside textStyle', () => {
+    const schema = getSchema(extensions);
+    expect(schema.marks.charStyle.rank).toBeLessThan(schema.marks.textStyle.rank);
+    const html = generateHTML({
+      type: 'doc',
+      content: [{ type: 'paragraph', content: [{ type: 'text', text: 'x',
+        marks: [{ type: 'textStyle', attrs: { fontSize: '10pt' } }, { type: 'charStyle', attrs: { name: 'Code' } }] }] }],
+    }, extensions);
+    expect(html.indexOf('data-char-style')).toBeLessThan(html.indexOf('font-size'));
+  });
+});