fix(cli): emit recursive JSON reports to stdout

[rioyu123]

Summary

• emit the existing recursive combined JSON document to stdout when --format json is used without --output
• route recursive human-readable status, progress, scores, summaries, verbose output, and scan advisories to stderr so stdout remains machine-readable
• preserve the existing JSON file schema, output bounds, exit codes, and terminal/file behavior
• retain a parseable combined JSON document when an individual child scan fails

Fixes #449.

Verification

• uv run --extra dev pytest tests/unit/test_cli.py -q (109 passed, 2 skipped)
• uv run --extra dev ruff check src/ tests/
• uv run --extra dev ruff format --check src/ tests/
• regression coverage parses JSON stdout for verbose recursive scans, wrapper advisories, and child-scan failures
• full Windows unit selection before the final CLI-only follow-up: 3944 passed, 26 skipped, 4 xfailed; 23 pre-existing platform failures remain in CRLF, symlink/mkfifo, secure-open, runtime-isolation, and release-script tests