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/docs/design-system/README.md

@@ -1,6 +1,6 @@
 # Design System Documentation
 
-**FastNext Template Design System** - A comprehensive guide to building consistent, accessible, and beautiful user interfaces.
+**PragmaStack Design System** - A comprehensive guide to building consistent, accessible, and beautiful user interfaces.
 
 ---
 
@@ -19,6 +19,11 @@
 
 ## 📖 Documentation Structure
 
+### Branding & Identity
+- **[Branding Guidelines](../branding/README.md)** 🎨
+  - Mission & Values
+  - Visual Identity (Logo, Colors, Typography)
+
 ### Getting Started
 
 - **[00. Quick Start](./00-quick-start.md)** ⚡