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/init-db.js

@@ -41,7 +41,29 @@ export default function initializeDatabase() {
       name TEXT NOT NULL,
       max_wait_days INTEGER DEFAULT 0,
       is_standard INTEGER NOT NULL DEFAULT 0
-    );    -- Table: project_tasks
+    );
+
+    -- Table: task_sets
+    CREATE TABLE IF NOT EXISTS task_sets (
+      set_id INTEGER PRIMARY KEY AUTOINCREMENT,
+      name TEXT NOT NULL,
+      description TEXT,
+      task_category TEXT CHECK(task_category IN ('design', 'construction')) NOT NULL,
+      created_at TEXT DEFAULT CURRENT_TIMESTAMP,
+      updated_at TEXT DEFAULT CURRENT_TIMESTAMP
+    );
+
+    -- Table: task_set_templates
+    CREATE TABLE IF NOT EXISTS task_set_templates (
+      set_id INTEGER NOT NULL,
+      task_template_id INTEGER NOT NULL,
+      sort_order INTEGER DEFAULT 0,
+      PRIMARY KEY (set_id, task_template_id),
+      FOREIGN KEY (set_id) REFERENCES task_sets(set_id) ON DELETE CASCADE,
+      FOREIGN KEY (task_template_id) REFERENCES tasks(task_id)
+    );
+
+    -- Table: project_tasks
     CREATE TABLE IF NOT EXISTS project_tasks (
       id INTEGER PRIMARY KEY AUTOINCREMENT,
       project_id INTEGER NOT NULL,
@@ -342,6 +364,24 @@ export default function initializeDatabase() {
 		console.warn("Migration warning:", e.message);
 	}
 
+	// Migration: Rename project_type to task_category in task_sets
+	try {
+		// Check if the old column exists and rename it
+		const tableInfo = db.prepare("PRAGMA table_info(task_sets)").all();
+		const hasOldColumn = tableInfo.some(col => col.name === 'project_type');
+		const hasNewColumn = tableInfo.some(col => col.name === 'task_category');
+
+		if (hasOldColumn && !hasNewColumn) {
+			// Rename the column
+			db.exec(`
+				ALTER TABLE task_sets RENAME COLUMN project_type TO task_category;
+			`);
+			console.log("✅ Renamed project_type to task_category in task_sets");
+		}
+	} catch (e) {
+		console.warn("Migration warning:", e.message);
+	}
+
 	// Generic file attachments table
 	db.exec(`
 		CREATE TABLE IF NOT EXISTS file_attachments (