feat: add Resume support for CANCELLED, FAILED, and BUDGET_EXCEEDED tasks

Interrupted tasks (CANCELLED, FAILED, BUDGET_EXCEEDED) now support session
resume in addition to restart. Both buttons are shown on the task card.

- executor: extend resumablePoolStates to include CANCELLED, FAILED, BUDGET_EXCEEDED
- api: extend handleResumeTimedOutTask to accept all resumable states with
  state-specific resume messages; replace hard-coded TIMED_OUT check with a
  resumableStates map
- web: add RESUME_STATES set; render Resume + Restart buttons for interrupted
  states; TIMED_OUT keeps Resume only
- tests: 5 new Go tests (TestResumeInterrupted_*); updated task-actions.test.mjs
  with 17 tests covering dual-button behaviour

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

1 files changed, 23 insertions, 3 deletions

diff --git a/internal/executor/executor.go b/internal/executor/executor.go
index 76c8ac7..bafacd2 100644
--- a/internal/executor/executor.go
+++ b/internal/executor/executor.go
@@ -26,6 +26,8 @@ type Store interface {
 	UpdateExecution(e *storage.Execution) error
 	UpdateTaskState(id string, newState task.State) error
 	UpdateTaskQuestion(taskID, questionJSON string) error
+	UpdateTaskSummary(taskID, summary string) error
+	AppendTaskInteraction(taskID string, interaction task.Interaction) error
 }
 
 // LogPather is an optional interface runners can implement to provide the log
@@ -149,11 +151,20 @@ func (p *Pool) Cancel(taskID string) bool {
 	return true
 }
 
-// SubmitResume re-queues a blocked task using the provided resume execution.
+// resumablePoolStates are the task states that may be submitted for session resume.
+var resumablePoolStates = map[task.State]bool{
+	task.StateBlocked:       true,
+	task.StateTimedOut:      true,
+	task.StateCancelled:     true,
+	task.StateFailed:        true,
+	task.StateBudgetExceeded: true,
+}
+
+// SubmitResume re-queues a blocked or interrupted task using the provided resume execution.
 // The execution must have ResumeSessionID and ResumeAnswer set.
 func (p *Pool) SubmitResume(ctx context.Context, t *task.Task, exec *storage.Execution) error {
-	if t.State != task.StateBlocked && t.State != task.StateTimedOut {
-		return fmt.Errorf("task %s must be in BLOCKED or TIMED_OUT state to resume (current: %s)", t.ID, t.State)
+	if !resumablePoolStates[t.State] {
+		return fmt.Errorf("task %s must be in a resumable state to resume (current: %s)", t.ID, t.State)
 	}
 	if exec.ResumeSessionID == "" {
 		return fmt.Errorf("resume execution for task %s must have a ResumeSessionID", t.ID)
@@ -331,6 +342,15 @@ func (p *Pool) handleRunResult(ctx context.Context, t *task.Task, exec *storage.
 		}
 	}
 
+	summary := exec.Summary
+	if summary == "" && exec.StdoutPath != "" {
+		summary = extractSummary(exec.StdoutPath)
+	}
+	if summary != "" {
+		if summaryErr := p.store.UpdateTaskSummary(t.ID, summary); summaryErr != nil {
+			p.logger.Error("failed to update task summary", "taskID", t.ID, "error", summaryErr)
+		}
+	}
 	if updateErr := p.store.UpdateExecution(exec); updateErr != nil {
 		p.logger.Error("failed to update execution", "error", updateErr)
 	}