docs: update README with comprehensive test results, CLI documentation, and enhanced feature descriptions

- Update key capabilities to include GPU marketplace, payments, billing, and governance
- Expand CLI section from basic examples to 12 command groups with 90+ subcommands
- Add detailed test results table showing 208 passing tests across 6 test suites
- Update documentation links to reference new CLI reference and coordinator API docs
- Revise test commands to reflect actual test structure (

cli/aitbc_cli/main.py

@@ -20,6 +20,7 @@ from .commands.simulate import simulate
 from .commands.admin import admin
 from .commands.config import config
 from .commands.monitor import monitor
+from .commands.governance import governance
 from .plugins import plugin, load_plugins
 
 
@@ -96,6 +97,7 @@ cli.add_command(simulate)
 cli.add_command(admin)
 cli.add_command(config)
 cli.add_command(monitor)
+cli.add_command(governance)
 cli.add_command(plugin)
 load_plugins(cli)