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/app/api/task-sets/[id]/route.js

@@ -0,0 +1,130 @@
+import {
+	getTaskSetById,
+	updateTaskSet,
+	deleteTaskSet,
+	addTaskTemplateToSet,
+	removeTaskTemplateFromSet,
+} from "@/lib/queries/tasks";
+import { NextResponse } from "next/server";
+import { withReadAuth, withUserAuth } from "@/lib/middleware/auth";
+import initializeDatabase from "@/lib/init-db";
+
+// GET: Get a specific task set with its templates
+async function getTaskSetHandler(req, { params }) {
+	initializeDatabase();
+	try {
+		const { id } = await params;
+		const taskSet = getTaskSetById(id);
+
+		if (!taskSet) {
+			return NextResponse.json(
+				{ error: "Task set not found" },
+				{ status: 404 }
+			);
+		}
+
+		return NextResponse.json(taskSet);
+	} catch (error) {
+		console.error("Error fetching task set:", error);
+		return NextResponse.json(
+			{ error: "Failed to fetch task set" },
+			{ status: 500 }
+		);
+	}
+}
+
+// PUT: Update a task set
+async function updateTaskSetHandler(req, { params }) {
+	initializeDatabase();
+	try {
+		const { id } = await params;
+		const updates = await req.json();
+
+		// Validate required fields
+		if (updates.name !== undefined && !updates.name.trim()) {
+			return NextResponse.json(
+				{ error: "Name cannot be empty" },
+				{ status: 400 }
+			);
+		}
+
+		if (updates.task_category !== undefined) {
+			const validTypes = ["design", "construction"];
+			if (!validTypes.includes(updates.task_category)) {
+				return NextResponse.json(
+					{ error: "Invalid task_category. Must be one of: design, construction" },
+					{ status: 400 }
+				);
+			}
+		}
+
+		// Handle template updates
+		if (updates.templates !== undefined) {
+			// Clear existing templates
+			// Note: This is a simple implementation. In a real app, you might want to handle this more efficiently
+			const currentSet = getTaskSetById(id);
+			if (currentSet) {
+				for (const template of currentSet.templates) {
+					removeTaskTemplateFromSet(id, template.task_id);
+				}
+			}
+
+			// Add new templates
+			if (Array.isArray(updates.templates)) {
+				for (let i = 0; i < updates.templates.length; i++) {
+					const template = updates.templates[i];
+					addTaskTemplateToSet(id, template.task_id, i);
+				}
+			}
+
+			// Remove templates from updates object so it doesn't interfere with task set update
+			delete updates.templates;
+		}
+
+		const result = updateTaskSet(id, updates);
+
+		if (result.changes === 0) {
+			return NextResponse.json(
+				{ error: "Task set not found" },
+				{ status: 404 }
+			);
+		}
+
+		return NextResponse.json({ success: true });
+	} catch (error) {
+		console.error("Error updating task set:", error);
+		return NextResponse.json(
+			{ error: "Failed to update task set", details: error.message },
+			{ status: 500 }
+		);
+	}
+}
+
+// DELETE: Delete a task set
+async function deleteTaskSetHandler(req, { params }) {
+	initializeDatabase();
+	try {
+		const { id } = await params;
+		const result = deleteTaskSet(id);
+
+		if (result.changes === 0) {
+			return NextResponse.json(
+				{ error: "Task set not found" },
+				{ status: 404 }
+			);
+		}
+
+		return NextResponse.json({ success: true });
+	} catch (error) {
+		console.error("Error deleting task set:", error);
+		return NextResponse.json(
+			{ error: "Failed to delete task set", details: error.message },
+			{ status: 500 }
+		);
+	}
+}
+
+// Protected routes - require authentication
+export const GET = withReadAuth(getTaskSetHandler);
+export const PUT = withUserAuth(updateTaskSetHandler);
+export const DELETE = withUserAuth(deleteTaskSetHandler);