feat: Add Markdown to ProseMirror converter

- New converter supports headings, lists, blockquotes, code blocks
- Documents now render with proper formatting in Outline
- Auto-update collection documentStructure on document creation
- Documents appear in sidebar automatically

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -2,6 +2,20 @@
 
 All notable changes to this project will be documented in this file.
 
+## [1.3.14] - 2026-01-31
+
+### Added
+
+- **Markdown to ProseMirror Converter:** New `src/utils/markdown-to-prosemirror.ts`
+  - Converts Markdown text to ProseMirror JSON format
+  - Supports: headings, paragraphs, lists, checkboxes, blockquotes, code blocks, hr
+  - Supports inline: bold, italic, links, inline code
+  - Documents now render with proper formatting in Outline
+
+- **Auto-update documentStructure:** `create_document` now updates collection's `documentStructure`
+  - New documents automatically appear in collection sidebar
+  - No manual database intervention needed
+
 ## [1.3.13] - 2026-01-31
 
 ### Fixed