fix: update dashboard dark theme to match shadcn v4

- Swap sidebar/content backgrounds so sidebar is lighter gray
- Update all dark mode tokens to shadcn v4 values (borders, cards, accents)
- Use Tailwind v4 blue color scale for chart colors in both modes
- Remove gradient from dashboard alpha banner

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: INQTR

src/app/globals.css

@@ -82,11 +82,11 @@
   --border: oklch(0.922 0 0);
   --input: oklch(0.922 0 0);
   --ring: oklch(0.708 0 0);
-  --chart-1: oklch(0.646 0.222 41.116);
-  --chart-2: oklch(0.60 0.118 184.704);
-  --chart-3: oklch(0.398 0.07 227.392);
-  --chart-4: oklch(0.828 0.189 84.429);
-  --chart-5: oklch(0.769 0.188 70.08);
+  --chart-1: var(--color-blue-300);
+  --chart-2: var(--color-blue-500);
+  --chart-3: var(--color-blue-600);
+  --chart-4: var(--color-blue-700);
+  --chart-5: var(--color-blue-800);
   --radius: 0.5rem;
   --sidebar: oklch(0.985 0 0);
   --sidebar-foreground: oklch(0.145 0 0);
@@ -118,34 +118,34 @@
 .dark {
   --background: oklch(0.145 0 0);
   --foreground: oklch(0.985 0 0);
-  --card: oklch(0.145 0 0);
+  --card: oklch(0.205 0 0);
   --card-foreground: oklch(0.985 0 0);
-  --popover: oklch(0.145 0 0);
+  --popover: oklch(0.205 0 0);
   --popover-foreground: oklch(0.985 0 0);
-  --primary: oklch(0.985 0 0);
+  --primary: oklch(0.922 0 0);
   --primary-foreground: oklch(0.205 0 0);
-  --secondary: oklch(0.205 0 0);
+  --secondary: oklch(0.269 0 0);
   --secondary-foreground: oklch(0.985 0 0);
-  --muted: oklch(0.205 0 0);
+  --muted: oklch(0.269 0 0);
   --muted-foreground: oklch(0.708 0 0);
-  --accent: oklch(0.205 0 0);
+  --accent: oklch(0.371 0 0);
   --accent-foreground: oklch(0.985 0 0);
-  --destructive: oklch(0.65 0.2 25); /* softer red for dark mode */
-  --border: oklch(0.205 0 0);
-  --input: oklch(0.205 0 0);
-  --ring: oklch(0.439 0 0);
-  --chart-1: oklch(0.488 0.243 264.376);
-  --chart-2: oklch(0.696 0.17 162.48);
-  --chart-3: oklch(0.769 0.188 70.08);
-  --chart-4: oklch(0.627 0.265 303.9);
-  --chart-5: oklch(0.645 0.246 16.439);
-  --sidebar: oklch(0 0 0);
+  --destructive: oklch(0.704 0.191 22.216);
+  --border: oklch(1 0 0 / 10%);
+  --input: oklch(1 0 0 / 15%);
+  --ring: oklch(0.556 0 0);
+  --chart-1: var(--color-blue-300);
+  --chart-2: var(--color-blue-500);
+  --chart-3: var(--color-blue-600);
+  --chart-4: var(--color-blue-700);
+  --chart-5: var(--color-blue-800);
+  --sidebar: oklch(0.205 0 0);
   --sidebar-foreground: oklch(0.985 0 0);
-  --sidebar-primary: oklch(0.985 0 0);
-  --sidebar-primary-foreground: oklch(0.205 0 0);
-  --sidebar-accent: oklch(0.145 0 0);
+  --sidebar-primary: oklch(0.488 0.243 264.376);
+  --sidebar-primary-foreground: oklch(0.985 0 0);
+  --sidebar-accent: oklch(0.269 0 0);
   --sidebar-accent-foreground: oklch(0.985 0 0);
-  --sidebar-border: oklch(0.205 0 0);
+  --sidebar-border: oklch(1 0 0 / 10%);
   --sidebar-ring: oklch(0.439 0 0);
 
   /* Surface levels - stacking depth (1=base, 2=elevated, 3=highest) */

src/components/dashboard/dashboard-banner.tsx

@@ -2,9 +2,8 @@ import { Github } from "lucide-react";
 
 export function DashboardBanner() {
   return (
-    <div className="relative overflow-hidden rounded-xl bg-linear-to-r from-indigo-500/10 via-purple-500/10 to-pink-500/10 border border-indigo-500/20 mb-8">
-      <div className="absolute inset-0 bg-grid-white/10 mask-[linear-gradient(0deg,white,rgba(255,255,255,0.5))] dark:bg-grid-black/10" />
-      <div className="relative flex flex-col sm:flex-row items-start sm:items-center justify-between gap-4 bg-background/50 backdrop-blur-sm px-4 py-3">
+    <div className="rounded-xl border border-indigo-500/20 mb-8">
+      <div className="flex flex-col sm:flex-row items-start sm:items-center justify-between gap-4 px-4 py-3">
         <div className="flex flex-col sm:flex-row sm:items-center gap-2 sm:gap-3">
           <div className="flex items-center gap-2">
             <span className="inline-flex items-center rounded-md bg-indigo-500/15 px-2 py-0.5 text-xs font-medium text-indigo-700 dark:text-indigo-300">