3e237e177a
* feat: add code-walkthrough backend (MCP tool, service, persistence, WS events) * feat: render agent code walkthroughs as line-anchored cards + editor window * test: add code-walkthrough re-emit mock-agent scenario * fix: rework code-walkthrough UX (floating card, line reveal, minimize, clickable file) * fix: improve code walkthrough editor UX * fix: backfill walkthrough launcher after websocket connect * fix: improve walkthrough requests and editor anchors * fix: clear walkthrough highlights on close * feat: add walkthrough discard and prompt customization * fix: send walkthrough requests through saved prompt * fix: support postgres built-in prompt seeding * fix: address walkthrough review feedback * fix: address walkthrough review follow-ups * fix: harden walkthrough lifecycle races * fix: reuse walkthrough notification cleanup * fix: guard stale walkthrough file opens * fix: abort stale file opens before paint * fix: stabilize github settings e2e readiness * fix: use stable github settings e2e selector