feat: Implement syntactic sugar and site-specific discovery config

- Add syntactic sugar for container transformation: .insertr containers → children get .insertr
- Fix discovery auto-running when disabled with site-specific config loading
- Add comprehensive styling test examples for HTML attribute preservation
- Include test input for syntactic sugar validation
- Update discovery defaults to respect developer intent (disabled by default)

TODO.md

@@ -484,3 +484,54 @@ The HTTP server has been successfully implemented and is production-ready:
 5. **✅ Performance** - Static file serving with dynamic content injection
 6. **✅ Multi-Site** - Single server manages multiple enhanced sites
 7. **✅ Zero Downtime** - Updates don't require site rebuilds or deploys
+
+## 🎯 **Future Class Extensions: Advanced Access Control** (Planned)
+
+### **Granular Permission System for `.insertr-gate`**
+
+**Current Implementation**: Simple boolean authentication gate for page-level editing access.
+
+**Future Enhancement Concept**: Role-based access control and section-level permissions for enterprise applications.
+
+#### **Potential Extended Gate Classes**
+```html
+<!-- Current: Simple page-level auth -->
+<div class="insertr-gate"></div>
+
+<!-- Future: Role-based section permissions -->
+<div class="admin-content insertr-gate-admin">
+  <div class="insertr-add">Admin-only dynamic content</div>
+</div>
+
+<div class="editor-section insertr-gate-editor">
+  <div class="insertr-content">Editor-level rich content</div>
+</div>
+
+<div class="premium-content insertr-gate-premium" data-auth-level="subscription">
+  <div class="insertr">Premium subscriber content</div>
+</div>
+```
+
+#### **Enterprise Use Cases**
+- **Multi-tenant Applications**: Different organizations editing separate content areas
+- **Editorial Workflows**: Writers, editors, and admins with different capabilities
+- **Subscription Content**: Different content areas for different subscription tiers
+- **Department Permissions**: Marketing vs Engineering vs Sales content areas
+- **Geographic Restrictions**: Region-specific editing permissions
+
+#### **Implementation Considerations**
+- **Configuration Complexity**: How to maintain zero-config philosophy while supporting complex permissions
+- **Role Definition**: Where and how to define roles and permissions
+- **Authentication Integration**: Extending current auth system vs external RBAC systems
+- **Fallback Behavior**: Graceful degradation for unauthorized users
+- **Performance Impact**: Permission checks shouldn't slow down regular site visitors
+
+#### **Integration Points**
+- **Authentik OIDC**: Leverage existing auth provider for role information
+- **Database Schema**: Extend current content system with permission metadata
+- **API Endpoints**: New endpoints for permission management and validation
+- **Editor Interface**: Dynamic interface based on user permissions
+
+**Priority**: Low - implement after core functionality is stable and enterprise customers request advanced permissions.
+
+**Design Principle**: Keep simple `.insertr-gate` as default, add optional complexity only when needed.