feat: set DaisyUI primary to brand #7ed6df

Extend the built-in 'light' theme via DaisyUI 5's @plugin theme block.
All btn-primary / text-primary / selected-state utilities now use the
brand color across the app.

src/style.css

@@ -1,6 +1,18 @@
 @import "tailwindcss";
-@plugin "daisyui";
+@plugin "daisyui" {
+  themes: light --default, dark --prefersdark;
+}
+
+@plugin "daisyui/theme" {
+  name: "light";
+  default: true;
+  prefersdark: false;
+  color-scheme: light;
+  --color-primary: #7ed6df;
+  --color-primary-content: #042027;
+}
 
 @theme {
   --font-sans: "Fredoka", ui-sans-serif, system-ui, sans-serif;
+  --color-brand: #7ed6df;
 }