🎨 Palette: Prevent trailing artifacts on dynamic CLI lines

[EiJackGH]

💡 What: Added \033[K (Erase in Line) ANSI escape sequence after \r for dynamic line updates and removed hardcoded padding spaces. Also added venv/ to .gitignore.
🎯 Why: Prevents text trailing artifacts ("ghosts") on lines that are updated dynamically if the new text is shorter than the old one, making the CLI UX much cleaner and less brittle than guessing padding lengths.
📸 Before/After: N/A
♿ Accessibility: Ensures cleaner and more predictable screen updates.

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PR created automatically by Jules for task 12066311186337391454 started by @EiJackGH

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