feat: Add option to prevent browser refresh (Ctrl+R, Ctrl+Shift+R)

[cubicj]

PR Checklist

• Have you checked if it works normally in all models? Ignore this if it doesn't use models.
• Have you checked if it works normally in all web, local, and node hosted versions? If it doesn't, have you blocked it in those versions?
• Have you added type definitions?

Description

This PR adds an option to prevent the browser's default refresh behavior when pressing Ctrl+R or Ctrl+Shift+R. This is useful for users who want to use these shortcuts for other purposes without accidentally refreshing the page.

What's New

• New preventBrowserRefresh option in Database interface
• Toggle control in Accessibility Settings page
• Keyboard event handler to block Ctrl+R and Ctrl+Shift+R when option is enabled
• Support for Korean and English languages

Implementation Details

• Added preventBrowserRefresh optional boolean field to Database interface
• Implemented keyboard event prevention in hotkey.ts when option is enabled
• Case-insensitive key detection to handle both Ctrl+R and Ctrl+Shift+R
• Added UI toggle in AccessibilitySettings.svelte for easy user control
• Included language strings in both ko.ts and en.ts

Usage

1. Go to Settings > Accessibility
2. Enable "Prevent Browser Refresh (Ctrl+R)" option
3. Both Ctrl+R and Ctrl+Shift+R will no longer refresh the page when enabled

Technical Changes

• database.svelte.ts: Added preventBrowserRefresh optional field to Database interface
• hotkey.ts: Added keyboard event detection with case-insensitive comparison to handle both Ctrl+R and Ctrl+Shift+R
• AccessibilitySettings.svelte: Added UI toggle for the option
• ko.ts/en.ts: Added language strings for the new option

This feature provides users with more control over keyboard shortcuts and prevents accidental page refreshes during chat sessions.