feat: expose changestats in API responses

- Add parseChangestatFromOutput/File helpers in internal/api/changestats.go
  to parse git diff --stat summary lines from execution stdout logs
- Wire parser in processResult: after each execution completes, scan the
  stdout log for git diff stats and persist via UpdateExecutionChangestats
- Tests: TestGetTask_IncludesChangestats (verifies processResult wiring),
  TestListExecutions_IncludesChangestats (verifies storage round-trip)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/internal/api/server.go b/internal/api/server.go
index 163f2b8..8290738 100644
--- a/internal/api/server.go
+++ b/internal/api/server.go
@@ -128,7 +128,16 @@ func (s *Server) forwardResults() {
 }
 
 // processResult broadcasts a task completion event via WebSocket and calls the notifier if set.
+// It also parses git diff stats from the execution stdout log and persists them.
 func (s *Server) processResult(result *executor.Result) {
+	if result.Execution.StdoutPath != "" {
+		if stats := parseChangestatFromFile(result.Execution.StdoutPath); stats != nil {
+			if err := s.store.UpdateExecutionChangestats(result.Execution.ID, stats); err != nil {
+				s.logger.Error("failed to store changestats", "execID", result.Execution.ID, "error", err)
+			}
+		}
+	}
+
 	event := map[string]interface{}{
 		"type":      "task_completed",
 		"task_id":   result.TaskID,