[Docs] Create comprehensive USER_MANUAL.md

[marctjones]

Summary

Create a complete user manual covering all features.

Suggested Sections

1. Introduction

   • What is ebpf-assist
   • Architecture overview
   • Prerequisites

2. Installation

   • User install
   • System install
   • Verifying installation

3. CLI Reference

   • All commands with examples
   • Flags and options
   • JSON output mode

4. MCP Server

   • Configuration for Claude Code
   • Available tools
   • Example workflows

5. eBPF Development

   • Creating programs from templates
   • Compiling
   • Loading and attaching
   • Testing with trigger commands
   • Reading output

6. MicroVM Isolation

   • When to use
   • Setup (kernel, rootfs)
   • VM management commands
   • Crash detection

7. Authentication

   • Polkit integration
   • Capability requirements
   • Running without sudo

8. Troubleshooting

   • Common errors
   • Debug mode
   • Verifier errors

9. API Reference

   • Unix socket protocol
   • MCP tool schemas

Location

docs/USER_MANUAL.md