feat: persist agent assignment before task execution

- Add UpdateTaskAgent to Store interface and DB implementation
- Call UpdateTaskAgent in Pool.execute to persist assigned agent/model
  to database before the runner starts
- Update runTask in app.js to pass selected agent as query param

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

1 files changed, 6 insertions, 0 deletions

diff --git a/internal/executor/executor.go b/internal/executor/executor.go
index bf209b7..475d150 100644
--- a/internal/executor/executor.go
+++ b/internal/executor/executor.go
@@ -28,6 +28,7 @@ type Store interface {
 	UpdateTaskQuestion(taskID, questionJSON string) error
 	UpdateTaskSummary(taskID, summary string) error
 	AppendTaskInteraction(taskID string, interaction task.Interaction) error
+	UpdateTaskAgent(id string, agent task.AgentConfig) error
 }
 
 // LogPather is an optional interface runners can implement to provide the log
@@ -435,6 +436,11 @@ func (p *Pool) execute(ctx context.Context, t *task.Task) {
 		}
 	}
 
+	// Persist the assigned agent (and model) to the database before running.
+	if err := p.store.UpdateTaskAgent(t.ID, t.Agent); err != nil {
+		p.logger.Error("failed to persist agent config", "error", err, "taskID", t.ID)
+	}
+
 	agentType := t.Agent.Type
 	if agentType == "" {
 		agentType = "claude"