docs: add AI-friendly documentation and code comments

Add comprehensive documentation for AI assistants:
- .cursorrules with project context and conventions
- ARCHITECTURE.md with technical details
- DEVELOPMENT.md with practical guides
- JSDoc comments in all JavaScript modules
- Update README.md with AI-Friendly Development section

This enables AI tools (Cursor, Claude Code, GitHub Copilot) to understand the project and generate code following CoreUI Vue patterns.

src/_nav.js

@@ -1,3 +1,26 @@
+/**
+ * _nav.js - Sidebar Navigation Configuration
+ *
+ * This file defines the structure and content of the sidebar navigation menu.
+ * The navigation is rendered by AppSidebar component using CoreUI nav components.
+ *
+ * Navigation item types:
+ * - CNavItem: Single navigation link
+ * - CNavGroup: Expandable group of navigation items
+ * - CNavTitle: Section title/divider
+ *
+ * Each item can have:
+ * - component: CoreUI component type ('CNavItem', 'CNavGroup', 'CNavTitle')
+ * - name: Display text
+ * - to: Vue Router path (for CNavItem)
+ * - icon: CoreUI icon name (from @coreui/icons)
+ * - badge: Optional badge with color and text
+ * - items: Array of child items (for CNavGroup)
+ * - href: External link URL
+ * - external: Boolean for external links
+ *
+ * @type {Array<Object>}
+ */
 export default [
   {
     component: 'CNavItem',