🎨 Palette: Add confirmation dialog for remove stage

[dhaatrik]

💡 What: Added a window.confirm dialog to the "Remove Stage" action in the Vehicle Assembly Building (VAB).
🎯 Why: Removing a stage deletes all parts attached to it. Adding a confirmation step prevents accidental data loss and improves the overall user experience by ensuring destructive actions are intentional.
📸 Before/After: Before, clicking "REMOVE" immediately deleted the stage. Now, it prompts with "Are you sure you want to remove this stage? All parts in it will be lost." before proceeding.
♿ Accessibility: Uses the native browser window.confirm dialog, which is inherently accessible to screen readers and keyboard navigation.

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PR created automatically by Jules for task 7352913517837073196 started by @dhaatrik

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