Replace "FastNext" branding with "PragmaStack" across the project

- Updated all references, metadata, and templates to reflect the new branding, including layout files, components, and documentation.
- Replaced hardcoded color tokens like `green-600` with semantic tokens (`success`, `warning`, etc.) for improved design consistency.
- Enhanced `globals.css` with new color tokens for success, warning, and destructive states using the OKLCH color model.
- Added comprehensive branding guidelines and updated the design system documentation to align with the new identity.
- Updated tests and mocks to reflect the branding changes and ensured all visual/verbal references match "PragmaStack".
- Added new `branding/README.md` and `branding` docs for mission, values, and visual identity definition.

frontend/src/app/[locale]/dev/page.tsx

@@ -14,7 +14,7 @@ import { Badge } from '@/components/ui/badge';
 import { Separator } from '@/components/ui/separator';
 
 export const metadata: Metadata = {
-  title: 'Design System Hub | FastNext Template',
+  title: 'Design System Hub | PragmaStack',
   description:
     'Interactive design system demonstrations with live examples - explore components, layouts, spacing, and forms built with shadcn/ui and Tailwind CSS',
 };
@@ -90,7 +90,7 @@ export default function DesignSystemHub() {
             </div>
             <p className="text-lg text-muted-foreground">
               Interactive demonstrations, live examples, and comprehensive documentation for the
-              FastNext design system. Built with shadcn/ui + Tailwind CSS 4.
+              PragmaStack design system. Built with shadcn/ui + Tailwind CSS 4.
             </p>
           </div>
         </div>