Add adapter for Cursor

[AgileKnow23]

Add a Cursor adapter for session-coherence

Goal: Let Cursor AI users read/write the session chronicle automatically.

What needs to happen

1. Create adapters/cursor/ directory
2. Add a .cursorrules file that instructs Cursor to:
   • Read ~/.session-coherence/chronicle.md at session start for context
   • Write chronicle entries at natural breakpoints
3. Add install instructions to the adapter README
4. Update the main README's adapter table

Reference

• Look at adapters/claude-code/ for the hook-based approach
• Cursor uses .cursorrules files for behavioral instructions
• The chronicle format is documented in the main README
• Keep it zero-dependency — just markdown file I/O

Acceptance criteria

• Cursor reads the chronicle for session context
• Cursor appends entries in the correct format
• Clear install instructions
• Main README adapter table updated

New to the project? Read the README first, then look at how the Claude Code adapter works.