🎨 Palette: Replace native confirm dialog with accessible soft confirmation

[Sczitzo]

💡 What: Replaced the native blocking window.confirm() dialog for the 'End Session' action in SessionConsole.tsx with an inline, state-based soft confirmation UI.

🎯 Why: Native browser confirm() dialogs are generally considered poor UX because they block the main thread, cannot be consistently styled across browsers/devices, and can sometimes be confusing for users with screen readers. The soft confirmation provides a much cleaner, integrated experience while still protecting users from accidental destructive actions.

📸 Before/After:
Before: Clicking 'End Session' triggered an unstyled native browser modal popup with "OK" and "Cancel".
After: Clicking 'End Session' dynamically transforms the button area into an inline layout with styled 'Confirm End' (red) and 'Cancel' (gray) buttons, along with a warning text below them.

♿ Accessibility:

• Added role="status" to the conditionally rendered warning text ("⚠️ This will generate the session summary."). This ensures that when the user clicks 'End Session', their screen reader immediately announces the consequence of the impending destructive action, preserving the context that was previously provided by the native confirm dialog.
• Maintained clear visual focus states (focus-visible-ring) on both the confirm and cancel buttons.

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PR created automatically by Jules for task 2200031832092286297 started by @Sczitzo

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Prevent double-clicks from confirming the end

When a facilitator double-clicks the left side of the original End Session button, the first click sets showEndConfirm, React can render these inline controls before the second click, and the second click lands on Confirm End, immediately emitting endSession. That makes a common accidental double-click bypass the confirmation step that the previous native dialog enforced, which is risky because ending a session generates the summary and transitions the session to ENDED.

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