docs(roadmap): mark #21 and #29 as done

#21 (Resumed /status JSON parity gap): resolved by the broader
Resumed local-command JSON parity gap work tracked as #26. Re-verified
on main HEAD 8dc6580 — the regression test passes.

#29 (CLI provider dispatch hardcoded to Anthropic): landed at 8dc6580.
ApiProviderClient dispatch now routes correctly based on
detect_provider_kind. Original filing preserved as trace record.

Author: code-yeongyu