issue: 4480494 .cursorrules with dev context

Add comprehensive Cursor rules file to accelerate team development by
providing rich context about libxlio architecture, patterns,
and workflows.

The enhanced .cursorrules includes:

* Arch deep dive: Socket interception, memory management, HW abstraction
* Configuration system: JSON schema, loading priority, access patterns
* Development workflow: Testing, debugging, performance profiling
* API integration patterns: socket API, XLIO Ultra API, app integration
* Troubleshooting guide: Common issues, debug commands, perf tuning
* Common development tasks: Step-by-step guides for adding features
* Quick reference: Essential commands, key files, configuration params

This provides Cursor with comprehensive context to:
- libxlio's kernel-bypass architecture and LD_PRELOAD mechanism
- Suggest appropriate code patterns and file locations
- Help with debugging and performance optimization
- Guide implementation of new features and protocols
- Provide accurate troubleshooting assistance

Signed-off-by: Tomer Cabouly <[email protected]>

Author: tomerdbz