Function detectChanges

detectChanges(jsonPath: string, mdPath: string): DetectionResult
Detect whether JSON and/or Markdown have changed. Strategy:
1. Parse both JSON and Markdown to document objects.
2. If documents are identical, no change.
3. If documents differ, use file modification times to determine which was edited more recently. The newer file is considered the "changed" one. If modification times are very close (< 100ms), treat as conflict.
Parameters
- jsonPath: string
  Path to JSON file
- mdPath: string
  Path to Markdown file (single or multi-doc)
Returns DetectionResult
Detection result with jsonChanged, mdChanged, and conflict flags
Example
```
const result = detectChanges("doc.spm.json", "doc.spm.md");
if (result.conflict) throw new Error("Both files changed");
```
- Defined in sync.ts:51