[WIP] Add local video compression tool inspired by WebP converter

[Copilot]

Thanks for asking me to work on this. I will get started on it and keep this PR's description up to date as I form a plan and make progress.

Original prompt

Let's add another tool to the set. The idea is to build a local video compression tool. It should be inspired by the WebP converter. The user should be able to process video locally and select quality. We should use ffmpeg under the hood.

What we need:

• area for to drag n drop / select video
• way to set compression level
• checkbox to autodownload video

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[peckz]

@copilot can you make this one work?