🎨 Palette: Add explicit visual indicator for truncated tasks in TodoDrawer

[google-labs-jules]

💡 What: Added a "... and X more tasks" indicator at the bottom of the TodoDrawer when the number of TODO items exceeds maxVisible.
🎯 Why: When users have many tasks, silently truncating the list causes them to lose context and assume there are no more tasks. This preserves situational awareness.
📸 Before/After: Before, a long list just abruptly ended. After, there's a helpful indicator if tasks are hidden.
♿ Accessibility: Adds semantic clarity (via text) that the list is incomplete, improving understanding without changing existing functionality.

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PR created automatically by Jules for task 4865346768581291364 started by @YoungSx

[google-labs-jules]

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