Clean up legacy code after unified architecture implementation

- Remove obsolete cmd/auto_enhance.go command (replaced by unified enhance)
- Implement EnhanceInPlace method using unified pipeline
- Remove generated demo files from git tracking
- Verify all functionality works after cleanup:
  * go build successful
  * enhance command working correctly
  * unified pipeline (discovery → ID generation → content injection) verified
  * clean command structure (only enhance, serve, restore commands)

The codebase is now clean with no legacy auto-enhance references or stub implementations. All functionality consolidated into the unified Discoverer + Enhancer architecture.

internal/content/discoverer.go

@@ -133,12 +133,17 @@ func (disc *Discoverer) discoverNode(node *html.Node, result *FileDiscoveryResul
 	if disc.isGoodContainer(node) {
 		viableChildren := engine.FindViableChildren(node)
 		if len(viableChildren) >= 2 || (aggressive && len(viableChildren) >= 1) {
-			// Add insertr class to container for expansion
-			disc.addInsertrClass(node)
+			// Container expansion: add insertr class to each viable child, not the container
+			for _, child := range viableChildren {
+				if !disc.hasInsertrClass(child) {
+					disc.addInsertrClass(child)
+					result.IndividualsAdded++
+					result.ElementsEnhanced++
+				}
+			}
 			result.ContainersAdded++
-			result.ElementsEnhanced += len(viableChildren)
 
-			// Don't process children since container expansion handles them
+			// Don't process children since we just processed them
 			return
 		}
 	}