Fix bugs #24-27: calendar dedup, uncomplete tasks, planning view

Bug fixes:
- #24: Deduplicate calendar events across multiple calendars using
  summary + start time as key
- #25: Change event icon from calendar to clock to avoid confusion
  with date display
- #26: Add task uncomplete functionality via ReopenTask API for
  Todoist and closed=false for Trello
- #27: Restructure planning view with sections for Scheduled (timed
  events/tasks), Today (unscheduled), Quick Add, and Upcoming (3 days)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

3 files changed, 41 insertions, 5 deletions

diff --git a/internal/api/google_calendar.go b/internal/api/google_calendar.go
index 8dd48f0..2154351 100644
--- a/internal/api/google_calendar.go
+++ b/internal/api/google_calendar.go
@@ -76,15 +76,27 @@ func (c *GoogleCalendarClient) GetUpcomingEvents(ctx context.Context, maxResults
 		}
 	}
 
+	// Deduplicate events (same event may appear in multiple calendars)
+	seen := make(map[string]bool)
+	var uniqueEvents []models.CalendarEvent
+	for _, event := range allEvents {
+		// Use summary + start time as dedup key
+		key := event.Summary + event.Start.Format(time.RFC3339)
+		if !seen[key] {
+			seen[key] = true
+			uniqueEvents = append(uniqueEvents, event)
+		}
+	}
+
 	// Sort all events by start time
-	sort.Slice(allEvents, func(i, j int) bool {
-		return allEvents[i].Start.Before(allEvents[j].Start)
+	sort.Slice(uniqueEvents, func(i, j int) bool {
+		return uniqueEvents[i].Start.Before(uniqueEvents[j].Start)
 	})
 
 	// Limit to maxResults
-	if len(allEvents) > maxResults {
-		allEvents = allEvents[:maxResults]
+	if len(uniqueEvents) > maxResults {
+		uniqueEvents = uniqueEvents[:maxResults]
 	}
 
-	return allEvents, nil
+	return uniqueEvents, nil
 }
diff --git a/internal/api/interfaces.go b/internal/api/interfaces.go
index e2521f4..842814c 100644
--- a/internal/api/interfaces.go
+++ b/internal/api/interfaces.go
@@ -14,6 +14,7 @@ type TodoistAPI interface {
 	CreateTask(ctx context.Context, content, projectID string, dueDate *time.Time, priority int) (*models.Task, error)
 	UpdateTask(ctx context.Context, taskID string, updates map[string]interface{}) error
 	CompleteTask(ctx context.Context, taskID string) error
+	ReopenTask(ctx context.Context, taskID string) error
 	Sync(ctx context.Context, syncToken string) (*TodoistSyncResponse, error)
 }
 
diff --git a/internal/api/todoist.go b/internal/api/todoist.go
index 689bf10..b3d4579 100644
--- a/internal/api/todoist.go
+++ b/internal/api/todoist.go
@@ -442,3 +442,26 @@ func (c *TodoistClient) CompleteTask(ctx context.Context, taskID string) error {
 
 	return nil
 }
+
+// ReopenTask marks a completed task as active in Todoist
+func (c *TodoistClient) ReopenTask(ctx context.Context, taskID string) error {
+	url := fmt.Sprintf("%s/tasks/%s/reopen", c.baseURL, taskID)
+	req, err := http.NewRequestWithContext(ctx, "POST", url, nil)
+	if err != nil {
+		return fmt.Errorf("failed to create request: %w", err)
+	}
+	req.Header.Set("Authorization", "Bearer "+c.apiKey)
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("failed to reopen task: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusNoContent && resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return fmt.Errorf("todoist API error (status %d): %s", resp.StatusCode, string(body))
+	}
+
+	return nil
+}