The desktop chat view flattened Agent tool activity, which made sub-agent work
hard to follow and separated key evidence from the main conversation. This
change threads parent tool linkage through the server bridge and desktop store,
renders dispatched sub-agents as grouped cards with nested tool activity, and
moves long final outputs into a markdown preview dialog so the main transcript
stays readable on narrow layouts.
Constraint: Existing sessions and live websocket events both needed to preserve parent-child relationships
Rejected: Add brand-new subagent websocket event types | unnecessary protocol expansion when parent linkage already existed upstream
Rejected: Inline full sub-agent markdown in the card body | too cramped for narrow desktop chat layouts
Confidence: medium
Scope-risk: moderate
Reversibility: clean
Directive: Keep Agent card summaries compact; route long-form sub-agent output through the preview dialog unless the main chat layout is widened substantially
Tested: cd desktop && bun run test -- MessageList.test.tsx chatStore.test.ts
Tested: cd desktop && bun run lint
Tested: bun test src/server/__tests__/sessions.test.ts -t should\ reconstruct\ parent\ agent\ tool\ linkage\ from\ parentUuid\ chains
Not-tested: Full end-to-end visual verification against live CLI sessions with sub-agent text/thinking nested inline