Add ctx.register_cli_command() to PluginContext for general plugins and
discover_plugin_cli_commands() to memory plugin system. Plugins that
provide a register_cli(subparser) function in their cli.py are
automatically discovered during argparse setup and wired into the CLI.
- Remove 95-line hardcoded honcho argparse block from main.py
- Move honcho subcommand tree into plugins/memory/honcho/cli.py
via register_cli() convention
- hermes honcho setup now redirects to hermes memory setup (unified path)
- hermes honcho (no subcommand) shows status instead of running setup
- Future plugins can register CLI commands without touching core files
- PluginManager stores CLI registrations in _cli_commands dict
- Memory plugin discovery scans cli.py for register_cli at argparse time
main.py: -102 lines of hardcoded plugin routing
dd8a42bf7d