fix: make status and ship diagnostics non-consuming and mode-accurate

[chtnnh]

Problem

Read-only diagnostics call the consuming check path when KNOW_CODE_OVERRIDE=1, spending a one-shot allowance without a commit or push. Status also reports one combined commit/push answer even where push-mode validation differs.

Scope

Separate inspection from consumption and report authorization by operation.

Acceptance criteria

• Status and ship never consume an override allowance.
• Status presents distinct commit and push eligibility when they differ.
• Read-only diagnostic commands do not mutate gate/override state.
• Tests exercise pending trailer, changed HEAD, and override paths.