[dazzatronus]

Studio drew a clip with filter set as if it were unset, so previews, share links and shotstack inspect sheets differed from the render.

• The colour filters (boost, contrast, darken, greyscale, lighten, muted, negative) share one shader that ports the render's per-pixel maths on unpremultiplied colour. ColorMatrixFilter can't: saturation pivots on HSP brightness, so a linear matrix greys pure red to 76 where the render gives 139.
• blur is pixi's BlurFilter with edges repeated, like the render's clamped box blur. Blur strength is now set as each frame draws, so a capture, which resets the editor zoom to 1:1, blurs like the render. The zoom transition's blur read the same stale on-screen zoom and is fixed with it.
• Clips the render plays as video (video, html5, rich captions, image-to-video, animated rich text) stay unfiltered, as they render today.
• The filter runs before the wipe transition, the render's order.

Verify: shotstack inspect a 3×3 grid of one image under each filter, against inspect of its render at 1 s. Every tile's mean colour lands within 3 levels of the render's, and the blur radius matches (3 px at scale 0.32).

Risk: the WebGPU shader compiles under a WGSL validator but hasn't drawn a frame; Studio initialises WebGL.