Add subagent result delivery artifacts

projects/dotfiles/099-pi-subagent-child-activity-capture-implementation.md

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+---
+status: resolved
+claimed-by: "019fc05b-7c70-7d68-af2b-89e9b6b17950"
+claimed-at: "2026-08-01T22:44:20-04:00"
+resolved-at: "2026-08-01T22:56:57-04:00"
+parent: "[[094-pi-subagent-result-delivery-spec-task|Pi subagent result delivery specification]]"
+blocked-by:
+  - "[[096-pi-subagent-labeled-work-items-implementation|Pi subagent labeled work items]]"
+tags:
+  - ticket/implementation
+---
+
+# Pi subagent child activity capture
+
+## Question
+
+Capture structured child RPC or session activity in the subagent runner and supervisor so last-activity summaries and read-only inspection can be driven from current-session state.
+
+## What to build
+
+The child runner and supervisor should retain structured current-session activity events instead of only a coarse last event name.
+The captured model should support concise last-activity summaries for status/list/widget output and preserve enough message and tool lifecycle information to render a basic Pi-like child transcript later.
+Existing final-result collection through `get_last_assistant_text` should continue to work.
+
+## Acceptance criteria
+
+- [x] Child records retain structured activity events from RPC or session data.
+- [x] Activity capture includes enough message and tool lifecycle data to reconstruct a basic Pi-like child transcript.
+- [x] Status or list output can expose a concise current activity summary without dumping transcript bodies.
+- [x] Final result completion through `get_last_assistant_text` still works.
+- [x] Tests cover event capture, ordering where relevant, and state updates.
+
+## Implementation Notes
+
+Use the existing RPC event stream as the first feed.
+Do not assume an embeddable promptless `InteractiveMode` exists.
+
+Implemented on branch `subagent-labels` in commit `ede3c05 feat(pi): capture subagent activity events`.
+The RPC runner now forwards structured event payloads, the supervisor retains full current-session activity events behind `Supervisor.activity`, and status/list/widget surfaces expose summary-only `currentActivity` and `activityHistory` data.
+Verification passed with `nix shell nixpkgs#nodejs_24 nixpkgs#tsx -c tsx --test modules/agents/pi/extensions/subagents/supervisor.test.ts modules/agents/pi/extensions/subagents/runner.test.ts modules/agents/pi/extensions/subagents/ui.test.ts modules/agents/pi/extensions/subagents/config.test.ts` and `nix flake check`.
+Review found no blocking findings.
+A non-blocking risk note remains that full activity retention is unbounded in process memory for the current session.