fix(ai-serving): preserve explicit request encoding

apps/aether-gateway/src/ai_serving/planner/standard/family/payload.rs

@@ -15,7 +15,8 @@ use crate::ai_serving::planner::report_context::{
 use crate::ai_serving::planner::spec_metadata::local_standard_spec_metadata;
 use crate::ai_serving::planner::CandidateFailureDiagnostic;
 use crate::ai_serving::planner::{
-    build_ai_execution_decision_response, AiExecutionDecisionResponseParts,
+    build_ai_execution_decision_response, resolve_transport_request_gzip_policy,
+    AiExecutionDecisionResponseParts,
 };
 use crate::ai_serving::transport::{
     resolve_transport_execution_timeouts, resolve_transport_profile,
@@ -175,6 +176,7 @@ pub(super) async fn maybe_build_local_standard_decision_payload_for_candidate(
         transport_profile: _,
         request_redacted: _,
     } = resolved;
+    let request_gzip = resolve_transport_request_gzip_policy(&transport);
 
     let mut decision = build_ai_execution_decision_response(AiExecutionDecisionResponseParts {
         decision_is_stream: spec_metadata.require_streaming,
@@ -201,6 +203,8 @@ pub(super) async fn maybe_build_local_standard_decision_payload_for_candidate(
         provider_request_body: Some(provider_request_body),
         provider_request_body_base64: None,
         content_type: Some("application/json".to_string()),
+        content_encoding: None,
+        request_gzip,
         proxy,
         transport_profile,
         timeouts,