Function mock_semantic_memory 

pub async fn mock_semantic_memory() -> Result<Arc<SemanticMemory>, MemoryError>

Build a SemanticMemory that runs entirely in-process with no external dependencies.

• SQLite backend: :memory: (in-process, no file I/O)
• Vector backend: InMemoryVectorStore (cosine similarity search)
• LLM provider: MockProvider with embedding support enabled

Errors

Returns MemoryError if the in-memory SQLite cannot be initialised.