feat: Add comprehensive documentation suite and reorganize project structure

- Created complete documentation in docs/ directory
- Added PROJECT_OVERVIEW.md with feature highlights and getting started guide
- Added ARCHITECTURE.md with system design and technical details
- Added SECURITY.md with comprehensive security implementation guide
- Added DEVELOPMENT.md with development workflows and best practices
- Added DEPLOYMENT.md with production deployment instructions
- Added API.md with complete REST API documentation
- Added CONTRIBUTING.md with contribution guidelines
- Added CHANGELOG.md with version history and migration notes
- Reorganized all documentation files into docs/ directory for better organization
- Updated README.md with proper documentation links and quick navigation
- Enhanced project structure with professional documentation standards

f_scripts/shared/flagicon/flags/1x1/sn.svg

@@ -0,0 +1,8 @@
+<svg xmlns="http://www.w3.org/2000/svg" height="512" width="512" viewBox="0 0 512 512">
+  <g fill-rule="evenodd" stroke-width="1pt">
+    <path fill="#0b7226" d="M-.001 0h170.665v512H-.001z"/>
+    <path fill="#ff0" d="M170.664 0h170.665v512H170.664z"/>
+    <path fill="#bc0000" d="M341.329 0h170.665v512H341.329z"/>
+  </g>
+  <path fill="#0b7226" d="M196.962 351.726l22.145-71.823-60.4-46.46h74.498l24.158-76.048 22.145 76.048h76.51l-60.4 46.46 22.145 73.935-60.4-46.474z"/>
+</svg>