cli_schema: exercises `kebab schema` (text + --json) on a fresh-but-init'd
KB. Pins schema_version, kebab_version non-empty, capabilities.json_mode
true, capabilities.mcp_server false (future placeholder).
cli_error_wire: spawns `kebab --json --config <malformed.toml> ingest`
and verifies stderr emits a single error.v1 ndjson line with
code == "config_invalid". Non-JSON mode regression-pinned to keep the
legacy `error:` prefix. Note: --config /nonexistent silently falls back
to defaults (by design); a file that exists but fails TOML parsing is
the reliable trigger for config_invalid.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>