fix(cli): preserve full per-skill JSON payload in recursive scans (#228)

[rodboev]

Summary

skillspector scan --recursive --format json currently reduces each successful skills[] entry to a summary row and drops the full per-skill report contract that single-skill JSON already exposes. This rebases the branch onto current main, preserves the recursive JSON contract for integrations by embedding the full per-skill payload, and keeps current main's combined-file behavior for recursive non-JSON --output.

Closes #228

Root cause

_scan_multi_skill() already has the full graph result for each skill, including the rendered JSON report_body. The recursive JSON writer rebuilds each skills[] entry from only name, path, risk_score, risk_severity, and finding_count, so the richer per-skill JSON document is discarded before the combined file is written. This branch had also diverged from current main's recursive non-JSON output path, so the stale Markdown assertion was locking in behavior main no longer has.

Diff Notes

• Rebase onto current main, keeping the existing _result_body() helper and concatenated non-JSON --output writer.
• Parse successful per-skill JSON report_body values and merge them into each successful recursive skills[] entry while retaining the compatibility summary keys.
• Keep per-skill error entries unchanged.
• Update CLI regressions for recursive JSON fidelity, single-skill preservation, and recursive Markdown --output file behavior.

Scope

This stays on the CLI/report-contract boundary. It does not change analyzers, report-node schema, SARIF output, structured-skill discovery, baseline threading, provider behavior, or non-recursive output.

Verification

• .\.venv\Scripts\python.exe -m pytest tests/unit/test_cli.py (12 passed)
• uv run ruff check src/skillspector/cli.py tests/unit/test_cli.py
• uv run ruff format --check src/skillspector/cli.py tests/unit/test_cli.py

[rng1995]

The JSON payload implementation is sound on this branch's base, but the PR conflicts with current main and its non-JSON regression test locks in behavior that main has since fixed. Rebase, preserve current main's combined-file behavior for recursive non-JSON --output, integrate the JSON payload work, and rerun the CLI suite.