Add Trello Lists support for UI dropdowns

Expose Trello Lists in Board model to enable card creation UI:

- Add List model struct (ID, Name) to types.go
- Add Lists []List field to Board model
- Add GetLists method to TrelloAPI interface
- Refactor private getLists to return []models.List
- Update GetCards to build list map from slice
- Add public GetLists method wrapping private implementation
- Update GetBoardsWithCards to populate Lists field concurrently
- Update mock Trello client in tests to implement GetLists

All tests pass. Boards now include their lists for UI rendering.

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

1 files changed, 1 insertions, 0 deletions

diff --git a/internal/api/interfaces.go b/internal/api/interfaces.go
index 95cc0e7..31da0a8 100644
--- a/internal/api/interfaces.go
+++ b/internal/api/interfaces.go
@@ -19,6 +19,7 @@ type TodoistAPI interface {
 type TrelloAPI interface {
 	GetBoards(ctx context.Context) ([]models.Board, error)
 	GetCards(ctx context.Context, boardID string) ([]models.Card, error)
+	GetLists(ctx context.Context, boardID string) ([]models.List, error)
 	GetBoardsWithCards(ctx context.Context) ([]models.Board, error)
 	CreateCard(ctx context.Context, listID, name, description string, dueDate *time.Time) (*models.Card, error)
 	UpdateCard(ctx context.Context, cardID string, updates map[string]interface{}) error