Refactor CLI command registration around commander

[V3RON]

Summary

• Migrate the agent-cdp CLI to Commander so command parsing and validation live behind a dedicated src/cli/ Module family instead of a single hand-rolled dispatcher.
• Preserve the existing top-level help text, including the agent guidance to run agent-cdp skills get core, while keeping the current command names, flags, IPC payloads, and formatter output paths.
• Add focused CLI tests for preserved help output, Commander-backed dispatch, and the existing auto-target-selection behavior.

Backward Compatibility

• Existing command names, flag names, daemon IPC commands, and formatter-driven output remain compatible.
• The top-level help output still includes the full legacy command reference and agent guidance text.
• Error wording now comes from Commander for some parse failures and unknown commands/options, so exact error text may differ slightly even though the workflows and required flags remain the same.
• No daemon lifecycle, saved artifact format, or command defaults changed.

Risks

• Commander now owns parsing, so there is some regression risk around edge-case flag handling and parse-error wording.
• The custom top-level help is preserved by intercepting help requests before command execution, which could behave differently from the old parser for unusual argument values that literally equal --help.
• The CLI is now split across multiple command-family Modules, so future command additions need to follow the new registration pattern to keep locality.

Manual Testing

Setup:

• Use a checkout of this branch with dependencies installed.
• Have any CDP target available if you want to smoke-test target-aware commands.

Scenario:

1. Run pnpm test, pnpm typecheck, and pnpm build from the repo root and verify they all succeed.
2. Run pnpm agent-cdp -- help and verify the output still includes the full command list plus the instruction for LLM agents to run agent-cdp skills get core.
3. Run pnpm agent-cdp -- target list --url http://127.0.0.1:9222 and verify the command still accepts the existing flag shape and prints the usual target formatter output.
4. Run pnpm agent-cdp -- runtime eval --expr "process.version" against a selected target and verify the command still routes through the daemon and prints the existing runtime formatter output.