Remove Dgraph support from the codebase.

Dgraph-related functionality, configuration, and benchmarks have been removed from the project. This streamlines the codebase to focus on supported backends, specifically eliminating Dgraph references in favor of Neo4j and other implementations. Version bumped to reflect the changes.

pkg/database/interface.go

@@ -13,7 +13,7 @@ import (
 )
 
 // Database defines the interface that all database implementations must satisfy.
-// This allows switching between different storage backends (badger, dgraph, etc.)
+// This allows switching between different storage backends (badger, neo4j, etc.)
 type Database interface {
 	// Core lifecycle methods
 	Path() string