feat: add workflow studio and postgres support

src/proxy/conductor/conductor.rs

@@ -267,6 +267,7 @@ mod tests {
             route_id: Some(10),
             site_id: 20,
             account_id: Some(30),
+            account_unit_cost: None,
             base_url: "https://example.test/v1".into(),
             api_key: "key".into(),
             model: "gpt-5.5".into(),

src/proxy/conductor/types.rs

@@ -11,6 +11,7 @@ pub struct SelectedChannel {
     pub route_id: Option<i64>,
     pub site_id: i64,
     pub account_id: Option<i64>,
+    pub account_unit_cost: Option<f64>,
     pub base_url: String,
     pub api_key: String,
     pub model: String,