Add fx components 291-320 and the home scene; Kit.Shot, Kit.Toward

Palette cycling, sky, sun and moon, clouds, starfield, rain, snow,
petals, leaves, fireflies, waterfall, ocean, campfire, lava, aurora,
lightning, mountains and a season scene; scanlines, vignette, screen
shake, flash, dither fades, iris wipes, dissolves, mosaics, glitches,
sparkles, explosions and confetti. Home opens on a live scene in the
palette's season and a strip of all eight palettes.

pixel adds Canvas.Cycled, Sprite.At, SpriteOf, Kit.Toward and
Kit.Shot, which spends a cue under Reduce Motion so it never replays;
display exports Reduce. Gallery grids and the sidebar are one Tab
stop each.

gallery/registry.go

@@ -56,7 +56,7 @@ var Categories = []Category{
 	{"tabletop", "Tabletop", "桌游", icon.Crown},
 }
 
-var entries = slices.Concat(foundationEntries, layoutEntries, textEntries, displayEntries, inputEntries, controlEntries, feedbackEntries, navigationEntries, dataEntries, recordEntries, overlayEntries, popupEntries, datetimeEntries, timeEntries, chartEntries, plotEntries, gameEntries, rpgEntries, screenEntries, lootEntries)
+var entries = slices.Concat(foundationEntries, layoutEntries, textEntries, displayEntries, inputEntries, controlEntries, feedbackEntries, navigationEntries, dataEntries, recordEntries, overlayEntries, popupEntries, datetimeEntries, timeEntries, chartEntries, plotEntries, gameEntries, rpgEntries, screenEntries, lootEntries, fxEntries, screenFxEntries)
 
 func Entries() []Entry { return entries }