Glassmorphism + gradient theme migration (app-wide)

Central restyle keyed on shadcn data-slots so all 13 pages inherit it without edits:
a soft gradient field on the body, frosted-glass surfaces (translucent --card/--popover
+ backdrop-blur + hairline borders) on cards, popovers, selects, sheets, and form fields,
gradient primary buttons with glass secondary/outline, and a gradient + blurred sidebar.
The content area is transparent so the gradient shows behind the glass. Inline-styled
gradient cards (Team view) are unaffected.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/src/components/AppShell.tsx

@@ -27,8 +27,11 @@ export function AppShell({ children }: { children: ReactNode }) {
   const logout = useAuth((s) => s.logout)
 
   return (
-    <div className="flex min-h-screen bg-background text-foreground">
-      <aside className="flex w-60 shrink-0 flex-col bg-sidebar text-sidebar-foreground">
+    <div className="flex min-h-screen text-foreground">
+      <aside
+        className="flex w-60 shrink-0 flex-col border-r border-white/10 text-sidebar-foreground backdrop-blur-xl"
+        style={{ background: 'linear-gradient(180deg, oklch(0.29 0.11 286) 0%, oklch(0.22 0.09 296) 100%)' }}
+      >
         <div className="flex items-center gap-3 px-5 py-4">
           <span className="grid size-8 place-items-center rounded-md bg-sidebar-primary font-bold text-sidebar-primary-foreground">
             T