feat(tasks): add periodic due-date check for recurring tasks

A recurring task's successor now also gets created once its due date
passes, independent of completion -- an ignored/overdue recurring task
no longer blocks the next occurrence from appearing. Runs every 15
minutes via a new goroutine in main.go, cancelled on shutdown.

1 files changed, 43 insertions, 0 deletions

diff --git a/internal/store/native_tasks.go b/internal/store/native_tasks.go
index 501c0bc..d4cc896 100644
--- a/internal/store/native_tasks.go
+++ b/internal/store/native_tasks.go
@@ -298,6 +298,49 @@ func (s *Store) SetNextOccurrenceOverride(id string, date time.Time) error {
 	return checkRowsAffected(result)
 }
 
+// GetSeriesNeedingNextIteration returns the latest row of every recurring
+// series whose due_date has arrived (<= now) and which has no newer row
+// yet in its series -- regardless of completed state, so a series whose
+// synchronous CreateNextIteration call (from CompleteNativeTask) somehow
+// failed still gets healed on the next tick, and so an uncompleted,
+// ignored recurring task doesn't block its successor from appearing.
+func (s *Store) GetSeriesNeedingNextIteration(now time.Time) ([]models.Task, error) {
+	rows, err := s.db.Query(`
+		SELECT id, content, description, project_name, due_date, priority, completed, labels, created_at,
+		       recurrence_freq, recurrence_interval, recurrence_weekdays, recurrence_series_id, next_occurrence_override
+		FROM native_tasks t1
+		WHERE recurrence_series_id != ''
+		  AND due_date IS NOT NULL AND due_date <= ?
+		  AND NOT EXISTS (
+		    SELECT 1 FROM native_tasks t2
+		    WHERE t2.recurrence_series_id = t1.recurrence_series_id
+		      AND (t2.due_date > t1.due_date
+		           OR (t2.due_date = t1.due_date AND t2.created_at > t1.created_at))
+		  )
+	`, now)
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = rows.Close() }()
+	return scanNativeTasks(rows)
+}
+
+// AdvanceDueRecurringTasks creates the next iteration for every recurring
+// series whose latest row is due (or overdue) and has no successor yet.
+// Returns the number of iterations created.
+func (s *Store) AdvanceDueRecurringTasks(now time.Time) (int, error) {
+	series, err := s.GetSeriesNeedingNextIteration(now)
+	if err != nil {
+		return 0, err
+	}
+	for _, task := range series {
+		if err := s.CreateNextIteration(task); err != nil {
+			return 0, err
+		}
+	}
+	return len(series), nil
+}
+
 // checkRowsAffected returns ErrNativeTaskNotFound if the update matched no
 // rows -- mirrors the RowsAffected() check already used in sqlite.go's
 // ApproveAgentSession/DenyAgentSession for the same "silent 0-row update"