fix: resolve misleading empty state when searching in TaskLibrary

[Abhishek2005-ard]

Description

This PR improves the user experience in the TaskLibrary.jsx component by resolving a confusing edge case with the search functionality.

Previously, searching for a task that yielded zero results would inadvertently trigger the generic <EmptyState /> component. Since the EmptyState component is designed to prompt users to add their first task when their entire library is empty, displaying it during a failed search made it appear as if the user's tasks were completely deleted.

Changes Made

• Updated the conditional rendering logic in the Task List container.
• If the entire library is empty (tasks.length === 0), it renders the standard EmptyState component prompting them to create a task.
• If the user has tasks but their search yields no results, it now renders a contextual "No tasks found" message showing their specific search query.

Testing

• Verified that a completely empty task library still shows the correct "Add Task" empty state.
• Verified that searching for a non-existent task now correctly shows the contextual "We couldn't find anything matching '[query]'" message.

close #1385