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)

internal/content/site_manager.go

@@ -13,11 +13,12 @@ import (
 
 // SiteConfig represents configuration for a registered site
 type SiteConfig struct {
-	SiteID      string `yaml:"site_id"`
-	Path        string `yaml:"path"`        // Served path (enhanced output)
-	SourcePath  string `yaml:"source_path"` // Source path (for enhancement)
-	Domain      string `yaml:"domain,omitempty"`
-	AutoEnhance bool   `yaml:"auto_enhance"`
+	SiteID      string           `yaml:"site_id"`
+	Path        string           `yaml:"path"`        // Served path (enhanced output)
+	SourcePath  string           `yaml:"source_path"` // Source path (for enhancement)
+	Domain      string           `yaml:"domain,omitempty"`
+	AutoEnhance bool             `yaml:"auto_enhance"`
+	Discovery   *DiscoveryConfig `yaml:"discovery,omitempty"` // Override discovery settings
 }
 
 // SiteManager handles registration and enhancement of static sites
@@ -159,17 +160,27 @@ func (sm *SiteManager) EnhanceSite(siteID string) error {
 	}
 
 	// Create enhancer with auth provider for this operation
-	defaultConfig := EnhancementConfig{
-		Discovery: DiscoveryConfig{
-			Enabled:    true,
-			Aggressive: false,
-			Containers: true,
-			Individual: true,
-		},
+	// Discovery disabled by default - developers should explicitly mark elements with class="insertr"
+	discoveryConfig := DiscoveryConfig{
+		Enabled:    false, // Changed from true - respect developer intent
+		Aggressive: false,
+		Containers: true,
+		Individual: true,
+	}
+
+	// Override with site-specific discovery config if provided
+	if site.Discovery != nil {
+		discoveryConfig = *site.Discovery
+		log.Printf("🔧 Using site-specific discovery config for %s: enabled=%v, aggressive=%v",
+			siteID, discoveryConfig.Enabled, discoveryConfig.Aggressive)
+	}
+
+	config := EnhancementConfig{
+		Discovery:        discoveryConfig,
 		ContentInjection: true,
 		GenerateIDs:      true,
 	}
-	enhancer := NewEnhancerWithAuth(sm.contentClient, siteID, defaultConfig, sm.authProvider)
+	enhancer := NewEnhancerWithAuth(sm.contentClient, siteID, config, sm.authProvider)
 
 	// Perform enhancement from source to output
 	if err := enhancer.EnhanceDirectory(sourcePath, outputPath); err != nil {