Implement unified task completion with cache sync (Phase 3 Step 7)

Add checkbox UI to Tasks tab for completing Todoist tasks and archiving
Trello cards. Fix cache synchronization so completed items stay gone
after page reload by deleting them from SQLite cache after API success.

- Add HandleCompleteAtom handler routing to Todoist/Trello APIs
- Add DeleteTask/DeleteCard store methods for cache removal
- Add htmx.process() calls after innerHTML updates in app.js
- Add comprehensive tests for completion and cache behavior

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

1 files changed, 258 insertions, 0 deletions

diff --git a/internal/store/sqlite_test.go b/internal/store/sqlite_test.go
index 3379a11..962a1bf 100644
--- a/internal/store/sqlite_test.go
+++ b/internal/store/sqlite_test.go
@@ -336,3 +336,261 @@ func TestGetNotes_SQLInjectionAttempt(t *testing.T) {
 	// and is not vulnerable to SQL injection via the LIMIT clause
 	fmt.Println("✓ LIMIT clause is properly parameterized")
 }
+
+// setupTestStoreWithTasks creates a test store with tasks table
+func setupTestStoreWithTasks(t *testing.T) *Store {
+	t.Helper()
+
+	tempDir := t.TempDir()
+	dbPath := filepath.Join(tempDir, "test.db")
+
+	db, err := sql.Open("sqlite3", dbPath)
+	if err != nil {
+		t.Fatalf("Failed to open test database: %v", err)
+	}
+
+	db.SetMaxOpenConns(1)
+
+	store := &Store{db: db}
+
+	schema := `
+		CREATE TABLE IF NOT EXISTS tasks (
+			id TEXT PRIMARY KEY,
+			content TEXT NOT NULL,
+			description TEXT,
+			project_id TEXT,
+			project_name TEXT,
+			due_date DATETIME,
+			priority INTEGER DEFAULT 1,
+			completed BOOLEAN DEFAULT FALSE,
+			labels TEXT,
+			url TEXT,
+			created_at DATETIME,
+			updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
+		);
+	`
+	if _, err := db.Exec(schema); err != nil {
+		t.Fatalf("Failed to create schema: %v", err)
+	}
+
+	return store
+}
+
+// setupTestStoreWithCards creates a test store with boards and cards tables
+func setupTestStoreWithCards(t *testing.T) *Store {
+	t.Helper()
+
+	tempDir := t.TempDir()
+	dbPath := filepath.Join(tempDir, "test.db")
+
+	db, err := sql.Open("sqlite3", dbPath)
+	if err != nil {
+		t.Fatalf("Failed to open test database: %v", err)
+	}
+
+	db.SetMaxOpenConns(1)
+
+	store := &Store{db: db}
+
+	schema := `
+		CREATE TABLE IF NOT EXISTS boards (
+			id TEXT PRIMARY KEY,
+			name TEXT NOT NULL,
+			updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
+		);
+		CREATE TABLE IF NOT EXISTS cards (
+			id TEXT PRIMARY KEY,
+			name TEXT NOT NULL,
+			board_id TEXT NOT NULL,
+			list_id TEXT,
+			list_name TEXT,
+			due_date DATETIME,
+			url TEXT,
+			updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
+		);
+	`
+	if _, err := db.Exec(schema); err != nil {
+		t.Fatalf("Failed to create schema: %v", err)
+	}
+
+	return store
+}
+
+// TestDeleteTask verifies that DeleteTask removes a task from the cache
+func TestDeleteTask(t *testing.T) {
+	store := setupTestStoreWithTasks(t)
+	defer store.Close()
+
+	// Save some tasks
+	tasks := []models.Task{
+		{
+			ID:          "task1",
+			Content:     "Task 1",
+			Description: "Description 1",
+			Priority:    1,
+			Completed:   false,
+			Labels:      []string{},
+			CreatedAt:   time.Now(),
+		},
+		{
+			ID:          "task2",
+			Content:     "Task 2",
+			Description: "Description 2",
+			Priority:    2,
+			Completed:   false,
+			Labels:      []string{},
+			CreatedAt:   time.Now(),
+		},
+		{
+			ID:          "task3",
+			Content:     "Task 3",
+			Description: "Description 3",
+			Priority:    3,
+			Completed:   false,
+			Labels:      []string{},
+			CreatedAt:   time.Now(),
+		},
+	}
+
+	if err := store.SaveTasks(tasks); err != nil {
+		t.Fatalf("Failed to save tasks: %v", err)
+	}
+
+	// Verify all 3 tasks exist
+	result, err := store.GetTasks()
+	if err != nil {
+		t.Fatalf("Failed to get tasks: %v", err)
+	}
+	if len(result) != 3 {
+		t.Fatalf("Expected 3 tasks, got %d", len(result))
+	}
+
+	// Delete task2
+	if err := store.DeleteTask("task2"); err != nil {
+		t.Fatalf("DeleteTask failed: %v", err)
+	}
+
+	// Verify only 2 tasks remain
+	result, err = store.GetTasks()
+	if err != nil {
+		t.Fatalf("Failed to get tasks after delete: %v", err)
+	}
+	if len(result) != 2 {
+		t.Errorf("Expected 2 tasks after delete, got %d", len(result))
+	}
+
+	// Verify task2 is gone
+	for _, task := range result {
+		if task.ID == "task2" {
+			t.Errorf("task2 should have been deleted but was found")
+		}
+	}
+
+	// Verify task1 and task3 still exist
+	foundTask1, foundTask3 := false, false
+	for _, task := range result {
+		if task.ID == "task1" {
+			foundTask1 = true
+		}
+		if task.ID == "task3" {
+			foundTask3 = true
+		}
+	}
+	if !foundTask1 {
+		t.Error("task1 should still exist")
+	}
+	if !foundTask3 {
+		t.Error("task3 should still exist")
+	}
+}
+
+// TestDeleteTask_NonExistent verifies that deleting a non-existent task doesn't error
+func TestDeleteTask_NonExistent(t *testing.T) {
+	store := setupTestStoreWithTasks(t)
+	defer store.Close()
+
+	// Delete a task that doesn't exist - should not error
+	err := store.DeleteTask("nonexistent")
+	if err != nil {
+		t.Errorf("DeleteTask on non-existent task should not error, got: %v", err)
+	}
+}
+
+// TestDeleteCard verifies that DeleteCard removes a card from the cache
+func TestDeleteCard(t *testing.T) {
+	store := setupTestStoreWithCards(t)
+	defer store.Close()
+
+	// First create a board
+	_, err := store.db.Exec(`INSERT INTO boards (id, name) VALUES (?, ?)`, "board1", "Test Board")
+	if err != nil {
+		t.Fatalf("Failed to create board: %v", err)
+	}
+
+	// Insert cards directly
+	cards := []struct {
+		id      string
+		name    string
+		boardID string
+	}{
+		{"card1", "Card 1", "board1"},
+		{"card2", "Card 2", "board1"},
+		{"card3", "Card 3", "board1"},
+	}
+
+	for _, card := range cards {
+		_, err := store.db.Exec(
+			`INSERT INTO cards (id, name, board_id, list_id, list_name) VALUES (?, ?, ?, ?, ?)`,
+			card.id, card.name, card.boardID, "list1", "To Do",
+		)
+		if err != nil {
+			t.Fatalf("Failed to insert card: %v", err)
+		}
+	}
+
+	// Verify all 3 cards exist
+	var count int
+	err = store.db.QueryRow(`SELECT COUNT(*) FROM cards`).Scan(&count)
+	if err != nil {
+		t.Fatalf("Failed to count cards: %v", err)
+	}
+	if count != 3 {
+		t.Fatalf("Expected 3 cards, got %d", count)
+	}
+
+	// Delete card2
+	if err := store.DeleteCard("card2"); err != nil {
+		t.Fatalf("DeleteCard failed: %v", err)
+	}
+
+	// Verify only 2 cards remain
+	err = store.db.QueryRow(`SELECT COUNT(*) FROM cards`).Scan(&count)
+	if err != nil {
+		t.Fatalf("Failed to count cards after delete: %v", err)
+	}
+	if count != 2 {
+		t.Errorf("Expected 2 cards after delete, got %d", count)
+	}
+
+	// Verify card2 is gone
+	var exists int
+	err = store.db.QueryRow(`SELECT COUNT(*) FROM cards WHERE id = ?`, "card2").Scan(&exists)
+	if err != nil {
+		t.Fatalf("Failed to check card2: %v", err)
+	}
+	if exists != 0 {
+		t.Errorf("card2 should have been deleted")
+	}
+}
+
+// TestDeleteCard_NonExistent verifies that deleting a non-existent card doesn't error
+func TestDeleteCard_NonExistent(t *testing.T) {
+	store := setupTestStoreWithCards(t)
+	defer store.Close()
+
+	// Delete a card that doesn't exist - should not error
+	err := store.DeleteCard("nonexistent")
+	if err != nil {
+		t.Errorf("DeleteCard on non-existent card should not error, got: %v", err)
+	}
+}