fix: prevent config editor dialog overflow when there are too many file structure sections

[NV4RE]

Description

This PR fixes the editor dialog overflow issue that occurs when the configuration file contains numerous sections. Previously, when a config file had many sections, the file structure sidebar would extend beyond the viewport height, causing the entire dialog to overflow. The fix adds proper height constraints and scrolling behavior to maintain a clean layout.

Related Tickets & Documents

No existing issue - implemented direct fix due to straightforward solution.

Note: Future enhancement could involve refactoring the layout to use CSS Grid for improved structure:

grid-template-areas:
  "header header"
  "editor structure"

Mobile & Desktop Screenshots/Recordings

Befor:

• File structure sidebar extended beyond viewport height
• Caused entire dialog to overflow
• Required vertical scrolling of whole interface

before.mov

After:

• Content properly contained within viewport
• File structure sidebar scrolls independently
• Clean, consistent layout maintained

after.mov

[NV4RE]

Sorry, wrong source branch