Fix lenght of non-beat clips in the pattern editor

[Itreza2]

This PR is correcting the following:

• The melody / automation / sample clips were displayed with a constant length. They now scale with the pattern length.
• The length of melody / automation clips was independent from the number of steps in the pattern, which was causing some weird and unexpected behaviors.

Before:

2026-05-04.17-43-10.mp4

After:

2026-05-04.17-45-30.mp4

To my knowledge, no currently opened issue would be resolved by this PR, but I could be wrong.

[Monospace-V]

Is this likely to break backward compatibility with projects that have a different step size in pattern editor than its contents? I ask because I probably have projects like that.
Also can you describe what you mean by "unexpected and weird behaviours"?

[Itreza2]

Also can you describe what you mean by "unexpected and weird behaviours"?

Sure !
For instance, when you add notes to a melody clip (or nodes to an automation clip) that belong to a pattern, the clip size is automatically updated the same way as in the song editor. This will not add steps to the pattern, but the duration of the pattern is the length of its longest clip, so you can end in a situation where the playback arrow just continue out of the window, which I find quite unexpected and weird.
On the contrary, reducing the amount of steps will not reduce the melody / automation / sample lengths (and the pattern duration), but only the beat clips lengths.

Maybe my explanations are confusing 😅​. I will capture a video when able to, to show what I mean.

[Itreza2]

Is this likely to break backward compatibility with projects that have a different step size in pattern editor than its contents?

You mean if you have clips inside a pattern that are longer than the amount of steps in the pattern ? Then yes, this would break your project and you would have to manually add steps to the pattern.

[Itreza2]

I will capture a video when able to, to show what I mean.

Like promised, I have updated the description with a before / after demonstration.

[regulus79]

I think this looks pretty cool!