T09b overlays: lightbox, spotlight and tour, floating toolbar, peek; images fill their box; overlays take focus back when its element leaves the tree

src/theme/palette.rs

@@ -96,6 +96,7 @@ mixable!(
         danger_subtle: Hsla,
         info_subtle: Hsla,
         backdrop: Hsla,
+        media_backdrop: Hsla,
         shadow: Hsla,
         tooltip_bg: Hsla,
         tooltip_fg: Hsla,
@@ -144,6 +145,7 @@ impl Palette {
             danger_subtle: c(0xffefec),
             info_subtle: c(0xebf4ff),
             backdrop: rgba(0x18161352).into(),
+            media_backdrop: rgba(0x0e0d0bf8).into(),
             shadow: c(0x181613),
             tooltip_bg: c(0x181613),
             tooltip_fg: c(0xfcfaf7),
@@ -209,6 +211,7 @@ impl Palette {
             danger_subtle: c(0x3a1d1b),
             info_subtle: c(0x19273a),
             backdrop: rgba(0x00000080).into(),
+            media_backdrop: rgba(0x000000f8).into(),
             shadow: c(0x000000),
             tooltip_bg: c(0x373533),
             tooltip_fg: c(0xf3f1f0),