(studio) Canvas zoom improvements (Zoom to cursor, Reset button, and border scaling bug)

[O1Anas]

1. Mouse wheel/trackpad zoom focuses into the center – Currently, mouse wheel/trackpad zoom always zooms into the center of the composition. It should zoom into the mouse pointer's location for intuitive navigation.

2. Reset zoom button – Currently, double-clicking on the canvas resets zoom (undocumented/hidden). I Suggest adding a visible, consistent 'Reset Zoom' button.

3. Canvas border expands inward when zooming – The gray border of the canvas grows thicker and eats into the preview canvas. This was previously reported (see PR fix(studio): canvas border expands when zooming — switch from CSS zoom to transform scale #810) and is not fixed (PR was closed & not merged); the issue still happens in the current release and appears connected to CSS zoom vs. transform: scale.

Zoom screenshots:

When zoomed out:

When zoomed in:

@func25

[O1Anas]

The "canvas border expands inward when zooming" bug also affects panning (added in PR #888 ). The expanded border blocks users from panning to the edges freely, especially on portrait videos/compositions.

There's also a bug in the panning feature: the zoom percentage overlay reappears when panning, but it should only appear during zoom actions. Ideally, zoom controls should live in the top bar rather than as an overlay in the preview canvas.

[miguel-heygen]

@O1Anas I'll take a look today, I found a few issues