Function update_conversation_context 

pub async fn update_conversation_context(
    interaction_type: String,
    content: HashMap<String, String>,
    entities: Vec<EntityItem>,
    relations: Vec<RelationItem>,
    code_reference: Option<CodeReference>,
    session_id: Uuid,
) -> Result<MCPToolResult, Error>

Record a single context update via the canonical PostCortexService::update_context path.