Function ensure_memory_bank_dir 

pub async fn ensure_memory_bank_dir(
    workspace_dir: &Path,
) -> Result<PathBuf, MemoryBankError>

Ensure the memory bank directory exists, creating it if necessary

Arguments

• workspace_dir - Root directory of the workspace

Returns

Path to the memory bank directory

Errors

Returns MemoryBankError::Io if directory creation fails