Add dynamic Shift-to-delete custom cursor and tooltip refresh

[Darkforge317]

Overview

Implements a responsive UX improvement for task rows, providing instant feedback when preparing to remove a task and its descendants via Shift-click.

Changes

• Instant Tooltip Refresh: Implemented a global KeyEventDispatcher to bypass Swing focus limits, forcing the tooltip container to update state instantly on Shift press/release without requiring mouse movement.
• Contextual Trash Cursor: Added a custom trash.png cursor state that maps seamlessly across all sub-components within a task row layout while Shift is active.
• State Persistence: Added a multi-component MouseAdapter hover loop to ensure the custom cursor persists when dragging across adjacent task rows while maintaining a held Shift key.
• Bug Fix: Fixed an inverted null-check constraint within addPrereqsFromContext() that was blocking automated prerequisite menu lookups.