fix(gateway): normalize Gemini Vertex embedding transport

apps/aether-gateway/src/execution_runtime/fallback.rs

@@ -2,7 +2,8 @@ use aether_contracts::{ExecutionPlan, ExecutionResult};
 use serde_json::Value;
 
 use crate::orchestration::{
-    resolve_local_failover_analysis_for_attempt, LocalFailoverAnalysis, LocalFailoverDecision,
+    resolve_local_failover_analysis_for_attempt, LocalFailoverAnalysis,
+    LocalFailoverClassification, LocalFailoverDecision,
 };
 use crate::AppState;
 
@@ -48,6 +49,15 @@ pub(crate) async fn analyze_local_candidate_failover_sync(
         return LocalFailoverAnalysis::use_default();
     }
 
+    if let Some(error) = result.error.as_ref() {
+        if !error.retryable && !error.failover_recommended {
+            return LocalFailoverAnalysis {
+                classification: LocalFailoverClassification::StopExecutionError,
+                decision: LocalFailoverDecision::StopLocalFailover,
+            };
+        }
+    }
+
     resolve_local_failover_analysis_for_attempt(
         state,
         plan,
@@ -326,14 +336,14 @@ pub(crate) fn resolve_core_stream_direct_finalize_report_kind(plan_kind: &str) -
 mod tests {
     use std::collections::BTreeSet;
 
-    use aether_contracts::ExecutionResult;
+    use aether_contracts::{ExecutionError, ExecutionErrorKind, ExecutionPhase, ExecutionResult};
     use aether_data::repository::provider_catalog::InMemoryProviderCatalogReadRepository;
     use aether_data_contracts::repository::provider_catalog::{
         StoredProviderCatalogEndpoint, StoredProviderCatalogKey, StoredProviderCatalogProvider,
     };
 
     use super::{
-        resolve_core_stream_error_finalize_report_kind,
+        analyze_local_candidate_failover_sync, resolve_core_stream_error_finalize_report_kind,
         resolve_core_sync_error_finalize_report_kind, should_fallback_to_control_stream,
         should_fallback_to_control_sync, should_retry_next_local_candidate_stream,
         should_retry_next_local_candidate_sync, should_stop_local_candidate_failover_stream,
@@ -607,6 +617,69 @@ mod tests {
         );
     }
 
+    #[tokio::test]
+    async fn sync_failover_honors_non_retryable_execution_error() {
+        let result = ExecutionResult {
+            request_id: "req-1".to_string(),
+            candidate_id: None,
+            status_code: 502,
+            headers: Default::default(),
+            body: None,
+            telemetry: None,
+            error: Some(ExecutionError {
+                kind: ExecutionErrorKind::Upstream5xx,
+                phase: ExecutionPhase::Finalize,
+                message: "provider returned HTTP 200 without visible model output".to_string(),
+                upstream_status: Some(200),
+                retryable: false,
+                failover_recommended: false,
+            }),
+        };
+        let local_report_context = serde_json::json!({
+            "candidate_index": 0,
+            "retry_index": 0,
+        });
+        let state = build_state_with_provider_config(None);
+        let plan = sample_plan();
+
+        let analysis = analyze_local_candidate_failover_sync(
+            &state,
+            &plan,
+            "openai_chat_sync",
+            Some(&local_report_context),
+            &result,
+            Some("provider returned HTTP 200 without visible model output"),
+        )
+        .await;
+
+        assert_eq!(
+            analysis.decision,
+            crate::orchestration::LocalFailoverDecision::StopLocalFailover
+        );
+        assert!(
+            !should_retry_next_local_candidate_sync(
+                &state,
+                &plan,
+                "openai_chat_sync",
+                Some(&local_report_context),
+                &result,
+                Some("provider returned HTTP 200 without visible model output"),
+            )
+            .await
+        );
+        assert!(
+            should_stop_local_candidate_failover_sync(
+                &state,
+                &plan,
+                "openai_chat_sync",
+                Some(&local_report_context),
+                &result,
+                Some("provider returned HTTP 200 without visible model output"),
+            )
+            .await
+        );
+    }
+
     #[tokio::test]
     async fn sync_retry_next_candidate_skips_video_follow_up_plan_kinds() {
         let result = ExecutionResult {