Implemented the Knowledge Repository Foundation

Implemented the Knowledge Repository foundation to provide a unified access layer for the entire Knowledge Foundation. By centralizing operations such as save, load, search, and delete into the repository, each component can interact with the KnowledgeDB without being aware of the underlying persistence mechanism. This unifies data access across the system while providing a foundation that can more easily accommodate future database changes, enhanced search capabilities, and deeper integration with RAG and other knowledge-based features.