Isolate standalone key wallet handling

crates/aether-ai-pipeline/src/contracts/auth_context.rs

@@ -1,5 +1,9 @@
 use serde::{Deserialize, Serialize};
 
+fn is_false(value: &bool) -> bool {
+    !*value
+}
+
 #[derive(Debug, Clone, Deserialize, Serialize)]
 pub struct ExecutionRuntimeAuthContext {
     pub user_id: String,
@@ -10,4 +14,6 @@ pub struct ExecutionRuntimeAuthContext {
     pub api_key_name: Option<String>,
     pub balance_remaining: Option<f64>,
     pub access_allowed: bool,
+    #[serde(default, skip_serializing_if = "is_false")]
+    pub api_key_is_standalone: bool,
 }

crates/aether-ai-pipeline/src/contracts/control_payloads.rs

@@ -268,6 +268,7 @@ mod tests {
                 api_key_name: None,
                 balance_remaining: Some(12.5),
                 access_allowed: true,
+                api_key_is_standalone: false,
             }),
         );