Avoid double `factory factory` command invocation

[miyaontherelay]

Problem

The globally installed CLI currently requires commands like:

factory factory run-once --config ./factory.config.json --dry-run
factory factory start --mode live --config ./factory.config.json

The repeated factory factory is awkward and confusing. The first factory is the executable and the second is the command namespace, but users reasonably expect the factory-specific CLI to expose factory actions directly.

Expected UX

Factory actions should be top-level commands from the global binary:

factory run-once --config ./factory.config.json --dry-run
factory start --mode live --config ./factory.config.json
factory status --config ./factory.config.json

This does not need backward compatibility for factory factory ...; remove or reject the nested form as part of the cleanup.

Possible approach

Make factory actions the primary top-level parser commands. If fleet commands still need to exist in this package, put them under a distinct namespace such as factory fleet ... or move them to the separate fleet binary.

Acceptance criteria

• factory run-once --config <path> [--dry-run] works.
• factory start --mode live --config <path> works.
• factory status --config <path> works.
• factory factory ... is no longer required and does not need to remain supported.
• README quick-start examples use the direct form.