Migrate read-only basectl reports to the shared output contract

[codeforester]

Goal

Migrate the remaining read-only report and listing commands to the shared output contract from #1692, using #1693 as the pilot.

Scope

• Workspace status, check, doctor, onboarding, and agent brief.
• History and logs reports.
• Trust, repo/release/gh inspection reports.
• Build/run list and other read-only project listings.

Artifact-format options such as export-context --format markdown|zip, internal command-protocol, and progress-oriented mutation commands remain separate contracts.

Acceptance criteria

• Each migrated command supports the common public formats where its data model is record/report-oriented.
• Existing JSON schemas and machine-readable envelopes remain compatible.
• TTY-aware text, headerless CSV/TSV, YAML, and JSON behavior is covered by focused tests.
• Structured output never mixes headers, footers, or diagnostics into stdout.
• Update command-specific help and report documentation as needed.

Depends on #1692 and #1693.