[GTK] GUI Console acts twice on Home/End keys #5767

Describe the bug

Pressing Home both:

• moves the caret to the start of the line, and
• scrolls the viewport to the start of the history

Pressing End both:

• moves the caret to the end of the line, and
• scrolls the viewport to the end of the history

Which is very annoying.

The observed behavior is on WSL2 (and been there from day one AFAIK), needs independent Linux testing.

To reproduce

Press Home/End with non-empty input and history.

Expected behavior

Shouldn't scroll the viewport.

Platform version

-----------RED & PLATFORM VERSION----------- 
RED: [ branch: "master" tag: #v0.6.6 ahead: 532 date: 16-Aug-2026/19:03:48 commit: #b492f75752cc6b3abb8136825e9448ced9a357f2 ]
PLATFORM: [ name: "Ubuntu 24.04.4 LTS" OS: 'Linux arch: 'x86_64 version: 6.18.33 build: {#1 SMP PREEMPT_DYNAMIC Thu Jun 18 21:54:43 UTC 2026} ]
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