recover: restore untracked work from recovery branch (no Gemini changes)

Recovered files with no Claude→Agent contamination:
- docs/adr/002-task-state-machine.md
- internal/api/logs.go/logs_test.go: task-level log streaming endpoint
- internal/api/validate.go/validate_test.go: POST /api/tasks/validate
- internal/api/server_test.go, storage/db_test.go: expanded test coverage
- scripts/reset-failed-tasks, reset-running-tasks
- web/app.js, index.html, style.css: frontend improvements
- web/test/: active-tasks-tab, delete-button, filter-tabs, sort-tasks tests

Manually applied from server.go diff (skipping Claude→Agent rename):
- taskLogStore field + validateCmdPath field
- DELETE /api/tasks/{id} route + handleDeleteTask
- GET /api/tasks/{id}/logs/stream route
- POST /api/tasks/{id}/resume route + handleResumeTimedOutTask
- handleCancelTask: allow cancelling PENDING/QUEUED tasks directly

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

1 files changed, 55 insertions, 0 deletions

diff --git a/internal/storage/db.go b/internal/storage/db.go
index 1aac754..b3df696 100644
--- a/internal/storage/db.go
+++ b/internal/storage/db.go
@@ -409,6 +409,61 @@ func (s *DB) DeleteTask(id string) error {
 	return nil
 }
 
+// RecentExecution is returned by ListRecentExecutions (JOIN with tasks for name).
+type RecentExecution struct {
+	ID         string     `json:"id"`
+	TaskID     string     `json:"task_id"`
+	TaskName   string     `json:"task_name"`
+	State      string     `json:"state"`
+	StartedAt  time.Time  `json:"started_at"`
+	FinishedAt *time.Time `json:"finished_at,omitempty"`
+	DurationMS *int64     `json:"duration_ms,omitempty"`
+	ExitCode   int        `json:"exit_code"`
+	CostUSD    float64    `json:"cost_usd"`
+	StdoutPath string     `json:"stdout_path"`
+}
+
+// ListRecentExecutions returns executions since the given time, joined with task names.
+// If taskID is non-empty, only executions for that task are returned.
+func (s *DB) ListRecentExecutions(since time.Time, limit int, taskID string) ([]*RecentExecution, error) {
+	query := `SELECT e.id, e.task_id, t.name, e.status, e.start_time, e.end_time, e.exit_code, e.cost_usd, e.stdout_path
+	FROM executions e
+	JOIN tasks t ON e.task_id = t.id
+	WHERE e.start_time >= ?`
+	args := []interface{}{since.UTC()}
+
+	if taskID != "" {
+		query += " AND e.task_id = ?"
+		args = append(args, taskID)
+	}
+	query += " ORDER BY e.start_time DESC LIMIT ?"
+	args = append(args, limit)
+
+	rows, err := s.db.Query(query, args...)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var results []*RecentExecution
+	for rows.Next() {
+		var re RecentExecution
+		var endTime time.Time
+		var stdoutPath sql.NullString
+		if err := rows.Scan(&re.ID, &re.TaskID, &re.TaskName, &re.State, &re.StartedAt, &endTime, &re.ExitCode, &re.CostUSD, &stdoutPath); err != nil {
+			return nil, err
+		}
+		re.StdoutPath = stdoutPath.String
+		if !endTime.IsZero() {
+			re.FinishedAt = &endTime
+			ms := endTime.Sub(re.StartedAt).Milliseconds()
+			re.DurationMS = &ms
+		}
+		results = append(results, &re)
+	}
+	return results, rows.Err()
+}
+
 // UpdateTaskQuestion stores the pending question JSON on a task.
 // Pass empty string to clear the question after it has been answered.
 func (s *DB) UpdateTaskQuestion(taskID, questionJSON string) error {