feat: implement ProjectTasksList component and update ProjectTasksPage to use it

feat: add date_completed column to project_tasks table in database initialization
feat: update project task status to set date_completed when marking as completed

src/app/project-tasks/page.js

@@ -1,4 +1,4 @@
-import ProjectTasksDashboard from "@/components/ProjectTasksDashboard";
+import ProjectTasksList from "@/components/ProjectTasksList";
 import PageContainer from "@/components/ui/PageContainer";
 import PageHeader from "@/components/ui/PageHeader";
 
@@ -7,9 +7,9 @@ export default function ProjectTasksPage() {
 		<PageContainer>
 			<PageHeader
 				title="Project Tasks"
-				description="Monitor pending tasks, overdue items, and recent activity across all projects"
+				description="View and manage tasks across all projects in a structured list format"
 			/>
-			<ProjectTasksDashboard />
+			<ProjectTasksList />
 		</PageContainer>
 	);
 }