fix(cli): status --json is documented but the flag doesn't exist

[blafourcade]

Problem

aidd_docs/memory/cli.md documents status --json as the machine-readable mode for CI integration. No command in src/application/commands/ registers a --json option.

Evidence

Verified against the built binary:

$ node dist/cli.js status --json
error: unknown option '--json'

Same result for doctor --json.

Why it matters

Any CI script or external tool written against the documented contract breaks immediately with a non-obvious commander error, not a clear "not supported yet" message.

Fix

Pick one:

• Implement --json on status (and ideally doctor), emitting the full report as machine-readable JSON on stdout, matching what the doc already promises.
• Or correct aidd_docs/memory/cli.md to state no machine-readable mode exists yet, removing the false contract.

Acceptance criteria

• status --json behavior matches what cli.md documents (implemented, or the doc is corrected to match reality)
• node dist/cli.js status --json no longer fails with "unknown option", if implemented

Found by a UI/terminal-UX audit of cli/ — full report: cli/aidd_docs/tasks/2026_07/2026_07_22_audit/ui.md.