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_templates/tpl_frontend/img/default-token.svg

@@ -0,0 +1,34 @@
+<svg width="256" height="256" viewBox="0 0 256 256" xmlns="http://www.w3.org/2000/svg">
+  <defs>
+    <linearGradient id="tokenGradient" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" style="stop-color:#FFD700;stop-opacity:1" />
+      <stop offset="100%" style="stop-color:#FFA500;stop-opacity:1" />
+    </linearGradient>
+    <filter id="shadow" x="-50%" y="-50%" width="200%" height="200%">
+      <feDropShadow dx="2" dy="4" stdDeviation="3" flood-color="#000000" flood-opacity="0.3"/>
+    </filter>
+  </defs>
+  
+  <!-- Outer circle -->
+  <circle cx="128" cy="128" r="120" fill="url(#tokenGradient)" filter="url(#shadow)" stroke="#B8860B" stroke-width="4"/>
+  
+  <!-- Inner circle -->
+  <circle cx="128" cy="128" r="90" fill="none" stroke="#FFFFFF" stroke-width="3" opacity="0.8"/>
+  
+  <!-- Center symbol -->
+  <g transform="translate(128, 128)">
+    <!-- Dollar-like symbol -->
+    <rect x="-3" y="-50" width="6" height="100" fill="#FFFFFF" rx="3"/>
+    <rect x="-25" y="-30" width="50" height="15" fill="#FFFFFF" rx="7"/>
+    <rect x="-25" y="15" width="50" height="15" fill="#FFFFFF" rx="7"/>
+    
+    <!-- Decorative elements -->
+    <circle cx="-35" cy="-35" r="4" fill="#FFFFFF" opacity="0.8"/>
+    <circle cx="35" cy="-35" r="4" fill="#FFFFFF" opacity="0.8"/>
+    <circle cx="-35" cy="35" r="4" fill="#FFFFFF" opacity="0.8"/>
+    <circle cx="35" cy="35" r="4" fill="#FFFFFF" opacity="0.8"/>
+  </g>
+  
+  <!-- Shine effect -->
+  <ellipse cx="100" cy="80" rx="20" ry="30" fill="#FFFFFF" opacity="0.3" transform="rotate(-30 100 80)"/>
+</svg>