Constant SCHEMA_V8 

pub const SCHEMA_V8: &str = "
    ALTER TABLE ai_spend ADD COLUMN consumer_type TEXT NOT NULL DEFAULT 'user';
    ALTER TABLE mcp_tool_calls ADD COLUMN consumer_type TEXT NOT NULL DEFAULT 'user';
";

Schema v8 (DW-113): add the consumer_type column to ai_spend and mcp_tool_calls for typed agent/user attribution. The column defaults to 'user' so pre-DW-113 rows and records that omit the field land as user traffic (the pre-existing default). Uses ALTER TABLE (additive) so existing databases migrate in place.