Corrección: fix(cli): refuse relative --target-dir in doctor, update, and uninstall (#388) #390

Source PR: #388
Branch: fix/target-dir-shared-validation
Head reviewed: 1227271

Push the fixes to the branch above; do not open a new pull request. Comment on the PR and on this issue when done.

Blocking findings

• Issue doctor --target-dir accepts relative paths while install refuses them as invalid_target #372 criterion satisfied only for relative/unclean targets; doctor and update still accept absolute targets install refuses as invalid_target (internal/cli/doctor.go:122): Issue doctor --target-dir accepts relative paths while install refuses them as invalid_target #372's Expected direction is explicit: 'a target that install would refuse as invalid_target should be refused the same way by every command that consumes --target-dir, so the directory-target contract stays consistent across the CLI.' At the reviewed head the shared guard validTargetDir (install.go:102) checks only path form (absolute + clean). install additionally refuses any absolute target that is missing or not a directory as error=invalid_target, exit 64 (install.go:119-121). doctor still forwards such a target at doctor.go:122 and reports presence=absent with exit 0 (doctor.go:134); a regular file yields presence=unreadable with exit 3 (exitConflict). update still stats the path at update.go:243 and returns reason=target_absent with exit 2 (writeUpdateRefusal returns exitUnknown=2). docs/operating.md:81, untouched by this PR, documents install's refusal set as 'the path is missing, relative, or not a directory', while the sentence added by this PR at docs/operating.md:82 claims only 'a relative or unclean --target-dir' is refused by doctor, update, and uninstall - the PR narrows the stated scope without reconciling it with the issue criterion or listing it under its Out of Scope section. The new test TestDirectoryTargetCommandsRefuseRelativeTargets exercises only relative and unclean targets, so the divergence is covered by no assertion. Note for triage: doctor's documented contract (docs/operating.md table) is to report a directory target's presence, so the issue criterion as written and the preserved presence=absent behavior are in tension - the intended scope needs an explicit decision rather than the silent narrowing.
  • Failure scenario: Given the absolute path /abs/missing that does not exist: cortex install --target-dir /abs/missing exits 64 with stderr error=invalid_target, but cortex doctor --target-dir /abs/missing exits 0 with stdout target=/abs/missing presence=absent, and cortex update --target-dir /abs/missing --catalog <catalog> --apply exits 2 with stdout ending reason=target_absent - none of them refuses the target the way install would, contradicting the quoted criterion. Given an absolute path that is a regular file: install exits 64 error=invalid_target, doctor exits 3 presence=unreadable, update exits 2 reason=target_absent. The commands still disagree on what a valid target is, which is the exact inconsistency doctor --target-dir accepts relative paths while install refuses them as invalid_target #372 reports.

Acceptance criteria

• Fixed: Issue doctor --target-dir accepts relative paths while install refuses them as invalid_target #372 criterion satisfied only for relative/unclean targets; doctor and update still accept absolute targets install refuses as invalid_target (internal/cli/doctor.go:122). The scenario below no longer reproduces: Given the absolute path /abs/missing that does not exist: cortex install --target-dir /abs/missing exits 64 with stderr error=invalid_target, but cortex doctor --target-dir /abs/missing exits 0 with stdout target=/abs/missing presence=absent, and cortex update --target-dir /abs/missing --catalog <catalog> --apply exits 2 with stdout ending reason=target_absent - none of them refuses the target the way install would, contradicting the quoted criterion. Given an absolute path that is a regular file: install exits 64 error=invalid_target, doctor exits 3 presence=unreadable, update exits 2 reason=target_absent. The commands still disagree on what a valid target is, which is the exact inconsistency doctor --target-dir accepts relative paths while install refuses them as invalid_target #372 reports.