Fix truncated doctor summary output

[WalksWithASwagger]

Summary

• preserve the doctor command exit status without terminating before stdout flushes
• restore the final critical issue summary when provider keys are absent

Verification

• npm run verify
• npm run env:audit
• npm run env:scan
• 519 tests passed

[github-actions]

Agentic Traceability

Verdict: needs-human

Checks:

• Linked GitHub issue present: no
• Branch naming matches contract: no
• PR title prefix matches contract: yes
• PR body includes Linear line when required: yes
• Linear keys found: none

Next actions:

• Add Closes #<issue> or Refs #<issue> to the PR body so GitHub remains the execution truth.
• Use codex/issue-<number>-<slug> for GitHub-only work outside the active Linear delivery lane.

[github-actions]

Agentic Traceability

Verdict: needs-human

Checks:

• Linked GitHub issue present: no
• Branch naming matches contract: no
• PR title prefix matches contract: yes
• PR body includes Linear line when required: yes
• Linear keys found: none

Next actions:

• Add Closes #<issue> or Refs #<issue> to the PR body so GitHub remains the execution truth.
• Use codex/issue-<number>-<slug> for GitHub-only work outside the active Linear delivery lane.