Route domain WallpaperTheme through render_wallpaper

The shell now reads snapshot.appearance.wallpaper and feeds the domain
WallpaperTheme directly into render_wallpaper. The chrome enum is
deleted; the four design themes (Dawn / Violet / Mint / Slate) all map
to base + upper-blob + lower-blob HSLA palettes that approximate the
design's radial gradients with GPUI's 2-stop linear gradient pair.

Switching themes via core.set_wallpaper_theme now propagates through
snapshots into the next render.

crates/ely_app/src/shell/chrome/mod.rs

@@ -20,4 +20,4 @@ pub(crate) use split_pane::{
     render_split_pane_header,
 };
 pub(crate) use topbar::render_topbar;
-pub(crate) use wallpaper::{WallpaperTheme, render_wallpaper};
+pub(crate) use wallpaper::render_wallpaper;

crates/ely_app/src/shell/chrome/wallpaper.rs

@@ -1,48 +1,23 @@
+use ely_domain::WallpaperTheme;
 use gpui::{
     Hsla, IntoElement, ParentElement, Styled, div, hsla, linear_color_stop, linear_gradient, rgb,
 };
 
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
-pub(crate) enum WallpaperTheme {
-    Dawn,
-}
-
-impl WallpaperTheme {
-    fn base(self) -> u32 {
-        match self {
-            Self::Dawn => 0xefe8e1,
-        }
-    }
-
-    fn upper_blob(self) -> Hsla {
-        match self {
-            Self::Dawn => hsla(351.0 / 360.0, 1.0, 0.91, 0.85),
-        }
-    }
-
-    fn lower_blob(self) -> Hsla {
-        match self {
-            Self::Dawn => hsla(228.0 / 360.0, 1.0, 0.86, 0.65),
-        }
-    }
-}
-
 pub(crate) fn render_wallpaper(theme: WallpaperTheme) -> impl IntoElement {
-    let upper = theme.upper_blob();
-    let lower = theme.lower_blob();
+    let palette = palette_for(theme);
 
     div()
         .absolute()
         .inset_0()
-        .bg(rgb(theme.base()))
+        .bg(rgb(palette.base))
         .child(
             div()
                 .absolute()
                 .inset_0()
                 .bg(linear_gradient(
                     225.0,
-                    linear_color_stop(upper, 0.0),
-                    linear_color_stop(transparent_like(upper), 0.55),
+                    linear_color_stop(palette.upper, 0.0),
+                    linear_color_stop(transparent_like(palette.upper), 0.55),
                 )),
         )
         .child(
@@ -51,12 +26,43 @@ pub(crate) fn render_wallpaper(theme: WallpaperTheme) -> impl IntoElement {
                 .inset_0()
                 .bg(linear_gradient(
                     45.0,
-                    linear_color_stop(lower, 0.0),
-                    linear_color_stop(transparent_like(lower), 0.62),
+                    linear_color_stop(palette.lower, 0.0),
+                    linear_color_stop(transparent_like(palette.lower), 0.62),
                 )),
         )
 }
 
+struct WallpaperPalette {
+    base: u32,
+    upper: Hsla,
+    lower: Hsla,
+}
+
+fn palette_for(theme: WallpaperTheme) -> WallpaperPalette {
+    match theme {
+        WallpaperTheme::Dawn => WallpaperPalette {
+            base: 0xefe8e1,
+            upper: hsla(351.0 / 360.0, 1.0, 0.91, 0.85),
+            lower: hsla(228.0 / 360.0, 1.0, 0.86, 0.65),
+        },
+        WallpaperTheme::Violet => WallpaperPalette {
+            base: 0xe9e2ee,
+            upper: hsla(263.0 / 360.0, 1.0, 0.88, 0.78),
+            lower: hsla(33.0 / 360.0, 1.0, 0.87, 0.60),
+        },
+        WallpaperTheme::Mint => WallpaperPalette {
+            base: 0xe6ece2,
+            upper: hsla(146.0 / 360.0, 0.69, 0.85, 0.82),
+            lower: hsla(40.0 / 360.0, 1.0, 0.86, 0.65),
+        },
+        WallpaperTheme::Slate => WallpaperPalette {
+            base: 0xd6dae3,
+            upper: hsla(218.0 / 360.0, 0.20, 0.85, 0.75),
+            lower: hsla(20.0 / 360.0, 0.0, 0.10, 0.18),
+        },
+    }
+}
+
 fn transparent_like(color: Hsla) -> Hsla {
     hsla(color.h, color.s, color.l, 0.0)
 }