feat: rebrand to Slate (logo, palette, copy, Launch button)

- Wordmark SVG + favicon (#FF1F8F → #00D4FF gradient)
- Page title: Slate — AI App Builder
- Header logo via inline component (no external font deps)
- Deploy button label -> Launch
- Chat placeholder + example prompt rebranded
- Replace upstream accent palette with magenta primary, add cyan2 for accents
- Settings tab notes upstream remains stackblitz-labs/bolt.diy

uno.config.ts

@@ -35,17 +35,29 @@ const BASE_COLORS = {
     950: '#0A0A0A',
   },
   accent: {
-    50: '#F8F5FF',
-    100: '#F0EBFF',
-    200: '#E1D6FF',
-    300: '#CEBEFF',
-    400: '#B69EFF',
-    500: '#9C7DFF',
-    600: '#8A5FFF',
-    700: '#7645E8',
-    800: '#6234BB',
-    900: '#502D93',
-    950: '#2D1959',
+    50: '#FFF1F8',
+    100: '#FFD7EC',
+    200: '#FFB1D9',
+    300: '#FF85C2',
+    400: '#FF52A8',
+    500: '#FF1F8F',
+    600: '#E60077',
+    700: '#B80060',
+    800: '#8A004A',
+    900: '#5C0033',
+    950: '#33001D',
+  },
+  cyan2: {
+    50: '#E6FBFF',
+    100: '#BFF4FF',
+    200: '#80E9FF',
+    300: '#40DCFF',
+    400: '#1FD7FF',
+    500: '#00D4FF',
+    600: '#00A6CC',
+    700: '#007F99',
+    800: '#005566',
+    900: '#002B33',
   },
   green: {
     50: '#F0FDF4',