Reuse check results for doctor JSON

[codeforester]

Summary

• Refactor basectl doctor --format json to build base findings from setup_collect_base_check_results.
• Translate shared check results from ok booleans into doctor status values and reuse recovery text for JSON fixes.
• Update doctor JSON tests to cover the shared machine-readable finding names.

Validation

• bats cli/bash/commands/basectl/tests/doctor.bats
• bash -n cli/bash/commands/basectl/subcommands/doctor.sh cli/bash/commands/basectl/tests/doctor.bats
• env -u BASE_HOME HOME=/private/tmp/base-review-home BASE_TEST_PYTHON=/Users/rameshhp/.base.d/base/.venv/bin/python bin/base-test
• git diff --check

Closes #328