feat: add task sets functionality with CRUD operations and UI integration

- Implemented NewTaskSetPage for creating task sets with templates.
- Created TaskSetsPage for listing and filtering task sets.
- Enhanced TaskTemplatesPage with navigation to task sets.
- Updated ProjectTaskForm to support task set selection.
- Modified PageHeader to support multiple action buttons.
- Initialized database with task_sets and task_set_templates tables.
- Added queries for task sets including creation, retrieval, and deletion.
- Implemented applyTaskSetToProject function for bulk task creation.
- Added test script for verifying task sets functionality.

src/lib/queries/tasks.js

@@ -413,3 +413,192 @@ export function updateProjectTask(taskId, updates, userId = null) {
 
 	return result;
 }
+
+// ===== TASK SETS =====
+
+// Get all task sets
+export function getAllTaskSets() {
+	const taskSets = db
+		.prepare("SELECT * FROM task_sets ORDER BY name ASC")
+		.all();
+
+	// Add templates to each task set
+	return taskSets.map(taskSet => {
+		const templates = db
+			.prepare(`
+				SELECT
+					tst.sort_order,
+					t.task_id,
+					t.name,
+					t.max_wait_days,
+					t.description
+				FROM task_set_templates tst
+				JOIN tasks t ON tst.task_template_id = t.task_id
+				WHERE tst.set_id = ?
+				ORDER BY tst.sort_order ASC
+			`)
+			.all(taskSet.set_id);
+
+		return { ...taskSet, templates };
+	});
+}
+
+// Get task sets by task category
+export function getTaskSetsByTaskCategory(taskCategory) {
+	const taskSets = db
+		.prepare("SELECT * FROM task_sets WHERE task_category = ? ORDER BY name ASC")
+		.all(taskCategory);
+
+	// Add templates to each task set
+	return taskSets.map(taskSet => {
+		const templates = db
+			.prepare(`
+				SELECT
+					tst.sort_order,
+					t.task_id,
+					t.name,
+					t.max_wait_days,
+					t.description
+				FROM task_set_templates tst
+				JOIN tasks t ON tst.task_template_id = t.task_id
+				WHERE tst.set_id = ?
+				ORDER BY tst.sort_order ASC
+			`)
+			.all(taskSet.set_id);
+
+		return { ...taskSet, templates };
+	});
+}
+
+// Get task set by ID with templates
+export function getTaskSetById(setId) {
+	const taskSet = db
+		.prepare("SELECT * FROM task_sets WHERE set_id = ?")
+		.get(setId);
+
+	if (taskSet) {
+		const templates = db
+			.prepare(`
+				SELECT
+					tst.sort_order,
+					t.task_id,
+					t.name,
+					t.max_wait_days,
+					t.description
+				FROM task_set_templates tst
+				JOIN tasks t ON tst.task_template_id = t.task_id
+				WHERE tst.set_id = ?
+				ORDER BY tst.sort_order ASC
+			`)
+			.all(setId);
+
+		return { ...taskSet, templates };
+	}
+
+	return null;
+}
+
+// Create a new task set
+export function createTaskSet(data) {
+	const result = db
+		.prepare(`
+			INSERT INTO task_sets (name, description, task_category, created_at, updated_at)
+			VALUES (?, ?, ?, datetime('now', 'localtime'), datetime('now', 'localtime'))
+		`)
+		.run(data.name, data.description || null, data.task_category);
+
+	return result.lastInsertRowid;
+}
+
+// Update a task set
+export function updateTaskSet(setId, data) {
+	const fields = [];
+	const values = [];
+
+	if (data.name !== undefined) {
+		fields.push("name = ?");
+		values.push(data.name);
+	}
+
+	if (data.description !== undefined) {
+		fields.push("description = ?");
+		values.push(data.description || null);
+	}
+
+	if (data.task_category !== undefined) {
+		fields.push("task_category = ?");
+		values.push(data.task_category);
+	}
+
+	fields.push("updated_at = datetime('now', 'localtime')");
+	values.push(setId);
+
+	const stmt = db.prepare(`
+		UPDATE task_sets
+		SET ${fields.join(", ")}
+		WHERE set_id = ?
+	`);
+
+	return stmt.run(...values);
+}
+
+// Delete a task set
+export function deleteTaskSet(setId) {
+	// Delete task set templates first (cascade should handle this, but being explicit)
+	db.prepare("DELETE FROM task_set_templates WHERE set_id = ?").run(setId);
+
+	// Delete the task set
+	return db.prepare("DELETE FROM task_sets WHERE set_id = ?").run(setId);
+}
+
+// Add task template to set
+export function addTaskTemplateToSet(setId, taskTemplateId, sortOrder = 0) {
+	return db
+		.prepare(`
+			INSERT OR REPLACE INTO task_set_templates (set_id, task_template_id, sort_order)
+			VALUES (?, ?, ?)
+		`)
+		.run(setId, taskTemplateId, sortOrder);
+}
+
+// Remove task template from set
+export function removeTaskTemplateFromSet(setId, taskTemplateId) {
+	return db
+		.prepare(`
+			DELETE FROM task_set_templates
+			WHERE set_id = ? AND task_template_id = ?
+		`)
+		.run(setId, taskTemplateId);
+}
+
+// Apply task set to project (bulk create project tasks)
+export function applyTaskSetToProject(setId, projectId, userId = null) {
+	// Get the task set with templates
+	const taskSet = getTaskSetById(setId);
+	if (!taskSet) {
+		throw new Error(`Task set with ID ${setId} not found`);
+	}
+
+	const createdTasks = [];
+	const language = getUserLanguage();
+
+	// Create project tasks for each template in the set
+	for (const template of taskSet.templates) {
+		const result = createProjectTask({
+			project_id: projectId,
+			task_template_id: template.task_id,
+			status: "pending",
+			priority: "normal",
+			created_by: userId,
+			assigned_to: null, // Will be assigned based on user role logic in createProjectTask
+		});
+
+		createdTasks.push(result.lastInsertRowid);
+
+		// Add system note for task set application
+		const logMessage = `${serverT("Task added from set", language)} "${taskSet.name}"`;
+		addNoteToTask(result.lastInsertRowid, logMessage, true, userId);
+	}
+
+	return createdTasks;
+}