Add emoji confetti bursts and component playground.

Support app.relay.emoji_confetti on jumbo emoji clicks with canvas physics,
per-emoji particle profiles, and a fixed overlay that does not affect scroll.
Also add a Vite playground for live component previews and theme hover preview.

src/app/features/settings/general/General.tsx

@@ -8,6 +8,7 @@ import React, {
 } from 'react';
 import dayjs from 'dayjs';
 import { as, Box, Button, Chip, color, config, Header, IconButton, Input, Menu, MenuItem, PopOut, RectCords, Scroll, Switch, Text, toRem } from 'folds';
+import { useSetAtom } from 'jotai';
 import { Icon, Icons } from '../../../components/icons';
 import { HexColorPicker } from 'react-colorful';
 import { isKeyHotkey } from 'is-hotkey';
@@ -24,6 +25,7 @@ import {
   LightTheme,
   Theme,
   ThemeKind,
+  themePreviewIdAtom,
   useSystemThemeKind,
   useThemeNames,
   useThemes,
@@ -41,28 +43,49 @@ type ThemeSelectorProps = {
   onSelect: (theme: Theme) => void;
 };
 const ThemeSelector = as<'div', ThemeSelectorProps>(
-  ({ themeNames, themes, selected, onSelect, ...props }, ref) => (
-    <Menu {...props} ref={ref}>
-      <Box direction="Column" gap="100" style={{ padding: config.space.S100 }}>
-        {themes.map((theme) => (
-          <MenuItem
-            key={theme.id}
-            size="300"
-            variant={theme.id === selected.id ? 'Primary' : 'Surface'}
-            radii="300"
-            onClick={() => onSelect(theme)}
-          >
-            <Text size="T300">{themeNames[theme.id] ?? theme.id}</Text>
-          </MenuItem>
-        ))}
-      </Box>
-    </Menu>
-  )
+  ({ themeNames, themes, selected, onSelect, ...props }, ref) => {
+    const setPreviewId = useSetAtom(themePreviewIdAtom);
+
+    useEffect(
+      () => () => {
+        setPreviewId(undefined);
+      },
+      [setPreviewId]
+    );
+
+    const clearPreview = () => setPreviewId(undefined);
+    const previewTheme = (theme: Theme) => setPreviewId(theme.id);
+
+    return (
+      <Menu
+        {...props}
+        ref={ref}
+        onMouseLeave={clearPreview}
+      >
+        <Box direction="Column" gap="100" style={{ padding: config.space.S100 }}>
+          {themes.map((theme) => (
+            <MenuItem
+              key={theme.id}
+              size="300"
+              variant={theme.id === selected.id ? 'Primary' : 'Surface'}
+              radii="300"
+              onMouseEnter={() => previewTheme(theme)}
+              onFocus={() => previewTheme(theme)}
+              onClick={() => onSelect(theme)}
+            >
+              <Text size="T300">{themeNames[theme.id] ?? theme.id}</Text>
+            </MenuItem>
+          ))}
+        </Box>
+      </Menu>
+    );
+  }
 );
 
 function SelectTheme({ disabled }: { disabled?: boolean }) {
   const themes = useThemes();
   const themeNames = useThemeNames();
+  const setPreviewId = useSetAtom(themePreviewIdAtom);
   const [themeId, setThemeId] = useSetting(settingsAtom, 'themeId');
   const [menuCords, setMenuCords] = useState<RectCords>();
   const selectedTheme = themes.find((theme) => theme.id === themeId) ?? LightTheme;
@@ -72,10 +95,16 @@ function SelectTheme({ disabled }: { disabled?: boolean }) {
   };
 
   const handleThemeSelect = (theme: Theme) => {
+    setPreviewId(undefined);
     setThemeId(theme.id);
     setMenuCords(undefined);
   };
 
+  const closeMenu = () => {
+    setPreviewId(undefined);
+    setMenuCords(undefined);
+  };
+
   return (
     <>
       <Button
@@ -99,7 +128,7 @@ function SelectTheme({ disabled }: { disabled?: boolean }) {
           <FocusTrap
             focusTrapOptions={{
               initialFocus: false,
-              onDeactivate: () => setMenuCords(undefined),
+              onDeactivate: closeMenu,
               clickOutsideDeactivates: true,
               isKeyForward: (evt: KeyboardEvent) =>
                 evt.key === 'ArrowDown' || evt.key === 'ArrowRight',
@@ -125,6 +154,7 @@ function SystemThemePreferences() {
   const themeKind = useSystemThemeKind();
   const themeNames = useThemeNames();
   const themes = useThemes();
+  const setPreviewId = useSetAtom(themePreviewIdAtom);
   const [lightThemeId, setLightThemeId] = useSetting(settingsAtom, 'lightThemeId');
   const [darkThemeId, setDarkThemeId] = useSetting(settingsAtom, 'darkThemeId');
 
@@ -145,15 +175,27 @@ function SystemThemePreferences() {
   };
 
   const handleLightThemeSelect = (theme: Theme) => {
+    setPreviewId(undefined);
     setLightThemeId(theme.id);
     setLTCords(undefined);
   };
 
   const handleDarkThemeSelect = (theme: Theme) => {
+    setPreviewId(undefined);
     setDarkThemeId(theme.id);
     setDTCords(undefined);
   };
 
+  const closeLightMenu = () => {
+    setPreviewId(undefined);
+    setLTCords(undefined);
+  };
+
+  const closeDarkMenu = () => {
+    setPreviewId(undefined);
+    setDTCords(undefined);
+  };
+
   return (
     <Box wrap="Wrap" gap="400">
       <SettingTile
@@ -179,7 +221,7 @@ function SystemThemePreferences() {
           <FocusTrap
             focusTrapOptions={{
               initialFocus: false,
-              onDeactivate: () => setLTCords(undefined),
+              onDeactivate: closeLightMenu,
               clickOutsideDeactivates: true,
               isKeyForward: (evt: KeyboardEvent) =>
                 evt.key === 'ArrowDown' || evt.key === 'ArrowRight',
@@ -220,7 +262,7 @@ function SystemThemePreferences() {
           <FocusTrap
             focusTrapOptions={{
               initialFocus: false,
-              onDeactivate: () => setDTCords(undefined),
+              onDeactivate: closeDarkMenu,
               clickOutsideDeactivates: true,
               isKeyForward: (evt: KeyboardEvent) =>
                 evt.key === 'ArrowDown' || evt.key === 'ArrowRight',