(ComponentsV2) Rendered Display Size Control for MediaGalleryItem Images

[whrvey]

Summary

Add support for controlling the rendered display size of images in MediaGalleryComponent, independent of the image's native resolution.

---

Problem

Currently, images rendered inside a MediaGalleryComponent are displayed at a size derived from their native resolution. This means a high-resolution image (e.g. 1920×1080) can expand the component's container to an unintended size, while a low-resolution image may render too small - with no way to control either from the payload.

There is no exposed property to constrain or scale how an image is visually presented, only what image is shown.

Example

When generating images via canvas, I'm forced to choose between two bad outcomes: render at a small canvas size so it looks proportional in the container (but the image is blurry), or render at a high resolution for quality (but it displays far too large).

Solution

A display_size property would eliminate this tradeoff entirely. Some possible solutions:

1. Scale factor - a float between 0.0 and 1.0 (e.g. 0.5 renders the image at 50% of its natural display size)
2. Explicit dimensions - width and/or height integer fields (in pixels or as a percentage of the container), with the renderer maintaining aspect ratio if only one axis is specified
3. Named size presets - e.g. "small", "medium", "large", "full" - for a simpler API