bug: incremental edit duplicates frontmatter and start of document when `\'` in title

[vezwork]

Document Before adding ✅ reaction to ### Render Components\' title with comment.tsx render component UI:

---
format: q2-debug
render-components:
  - /elliot/simple.tsx
  - /elliot/html.tsx
  - /elliot/comment.tsx
  - /elliot/kanban.tsx
source-location: full
---

## Welcome to Elliot's Demo Page[>> ❤️][>> ❤️][>> ❤️][>> ❤️][>> 🎉][>> 🎉][>> ❤️][>> dog][>> ❤️][>> 🎉][>> hey this is a comment!]

### Render Components\'

Document After:

---
format: q2-debug
render-components:
  - /elliot/simple.tsx
  - /elliot/html.tsx
  - /elliot/comment.tsx
  - /elliot/kanban.tsx
source-location: full
---

## Welcome to Elliot's Demo Page[>> ❤️][>> ❤️][>> ❤️][>> ❤️][>> 🎉][>> 🎉][>> ❤️][>> dog][>> ❤️][>> 🎉][>> hey this is a comment!]

### Render ---
format: [>> ✅]q2-debug
render-components:
  - /elliot/simple.tsx
  - /elliot/html.tsx
  - /elliot/comment.tsx
  - /elliot/kanban.tsx
source-location: full
---

## Welcome to Elliot's Demo Page[>> ❤️][>> ❤️][>> ❤️][>> ❤️][>> 🎉][>> 🎉][>> ❤️][>> dog][>> ❤️][>> 🎉][>> hey this is a comment!]

### Render Components\'

[cscheid]

Oof, that's actually terrible :( I'm still deep in websites mode but give me a couple of days.

[vezwork]

No rush! Not blocking me at all. Don't want to forget about it is all.