Extend PushDispatchHistory so /v1/agent/sync writes four sync.*
workflow-progress keys into WorkspaceState (last_dispatch_at,
last_agent_type, last_findings_count, last_status) in addition to the
existing BrainMemory + SyncRecord persistence. Plan resolves via
agent_plan_id first, plan_slug fallback. Missing plan is treated as
non-fatal — state writes are skipped, BrainMemory still persists.
Adds a three-case feature test covering direct id, slug fallback, and
the missing-plan safety branch.
Closes tasks.lthn.sh/view.php?id=93
Co-authored-by: Codex <noreply@openai.com>
Co-Authored-By: Virgil <virgil@lethean.io>
