New sequence appears gray after clearing the canvas in non-sync mode

[Zhirnoff]

Description:
When the user switches to the antisense chain while not in sync mode, the sense chain becomes grayed out. If the user then clears the canvas and starts typing a new sequence, the new sequence also appears grayed out, which is incorrect behavior.

Steps to Reproduce

1. Open sequence mode create sense and antisense chains and disable sync mode.
2. Switch to the antisense chain.
3. Notice that the sense chain becomes grayed out.
4. Click Clear Canvas.
5. Start typing a new sequence.

Actual behavior
The newly typed sequence is grayed out after clearing the canvas.

Expected behavior
A new sequence should be properly visible and not grayed out.
Clearing the canvas should reset any previous gray-out effect.

Video

2025-03-07_18h24_27.mp4

Desktop:

• OS: Windows 11
• Browser Chrome
• Version 133.0.6943.127 (Official Build) (64-bit)

Ketcher version
[Version 3.2.0-rc.1]
Indigo version
[Version 1.30.0-rc.1]
This bug was found while testing: #6254