[improve] improved interaction styling for the template editor

[Duansg]

What's changed?

The current template management has several user-unfriendly issues, as follows

1. Without modifications, the current window utilization is low, and most single-line text is hidden.
2. If content is accidentally entered or pasted without modifications, it requires separate restoration

Modification Details

Optimize the interactive style of the template editor

1. Default read-only mode: Even when not in edit mode, the interface remains in a single-column read-only display to ensure an optimal viewing experience and maximize window space utilization.
2. Live Side-by-Side Comparison: Only when the user clicks the Edit button (entering edit mode) will the editor instantly switch to a left-right comparison mode, ensuring modifications can be made while maintaining the original layout for comparison.

Checklist

• I have read the Contributing Guide
• I have written the necessary doc or comment.
• I have added the necessary unit tests and all cases have passed.

Add or update API

• I have added the necessary e2e tests and all cases have passed.

[tomsun28]

👍