Fixed horizontal tab scrollbar size & incorrect scroll range #1403

[rutul24591]

ℹ️ About the PR

Fixes #1403

Problem

When we go into full screen mode of any type of display screen in the app and when we have more than 12 screens open in the app first screen goes inside the left window in tab pane. So, it made very difficult to switch to it i.e initial items got clipped and user is not able to view.

Root Cause

Tabs were shrinking (flex-shrink: 1), reducing actual scrollable width
Missing whitespace-nowrap allowed layout inconsistencies
Scroll container width calculation was incorrect → browser rendered oversized scrollbar thumb

Impact

No breaking changes.
Only CSS fixes.

Changes

desktop-app/src/renderer/components/Previewer/IndividualLayoutToolBar/index.tsx

🖼️ Testing Scenarios / Screenshots

• Tested scroll from left. All initial items are now visible.
• Tested scroll from right. Full scrolling until the very end.
• Confirmed with going into full screen from multiple devices( Start, middle, end).

With full screen

without full screen

[CLAassistant]

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