Clarify basectl ci naming and CI-safe mode contract

[codeforester]

Problem

basectl ci is easy to misread as "run the CI pipeline" or "create a local CI/Ubuntu runner." In the current implementation, it is narrower: it delegates to setup, check, and doctor with CI-safe defaults such as non-interactive behavior, BASE_CI=true, CI=true, notification suppression, and JSON-capable output.

That behavior is useful, but the subcommand name can confuse users who expect it to run tests, launch GitHub Actions locally, or spin up an Ubuntu/Multipass instance.

Desired outcome

Make the command model self-explanatory so users understand that CI is a mode for Base setup/readiness/diagnostics, not a separate CI runner.

Scope

• Decide whether the long-term surface should remain basectl ci setup|check|doctor, move toward flags such as basectl check --ci --format json, or add clearer aliases while preserving compatibility.
• Update CLI help and docs to state plainly that basectl ci does not run project tests, create runners, launch Ubuntu, or execute GitHub Actions locally.
• Clarify the relationship among:
  • basectl ci check
  • basectl ci doctor
  • basectl ci setup
  • basectl test
  • bin/base-test
  • the optional linux-lab profile
• If a new alias or flag is introduced, update completions, command reference docs, and focused tests.
• Keep the existing behavior backward-compatible unless there is an explicit deprecation plan.

Non-goals

• Do not implement a local GitHub Actions runner.
• Do not make basectl ci create or mutate Ubuntu/Multipass VM instances.
• Do not make basectl ci replace basectl test or bin/base-test.
• Do not change manifest command trust behavior.

Acceptance criteria

• The CLI help text makes the CI-safe delegation model clear.
• docs/basectl-ci.md, docs/command-reference.md, and README references describe the difference between basectl ci and basectl test.
• The docs explicitly say that Ubuntu instances are created manually and that linux-lab only prepares/checks local VM tooling.
• Tests cover any changed help text, aliases, flags, or completion behavior.
• Existing basectl ci setup|check|doctor callers continue to work, or a deliberate deprecation path is documented.

Demo impact

New users should not come away thinking Base has a local CI runner. The intended story should be: Base exposes CI-safe readiness/setup/diagnostic commands that CI systems can compose with their own runners and test commands.