feat(openai): align GPT-5.6 and Codex request contracts

apps/aether-gateway/src/ai_serving/planner/specialized/files/decision.rs

@@ -7,7 +7,7 @@ use crate::ai_serving::planner::report_context::{
 };
 use crate::ai_serving::planner::spec_metadata::local_gemini_files_spec_metadata;
 use crate::ai_serving::planner::{
-    build_ai_execution_decision_response, resolve_transport_request_gzip_policy,
+    build_ai_execution_decision_response, resolve_transport_request_encoding_policy,
     AiExecutionDecisionResponseParts,
 };
 use crate::ai_serving::transport::{
@@ -124,7 +124,7 @@ pub(super) async fn maybe_build_local_gemini_files_decision_payload_for_candidat
         upstream_url,
         file_name: _,
     } = resolved;
-    let request_gzip = resolve_transport_request_gzip_policy(&transport);
+    let request_encoding = resolve_transport_request_encoding_policy(&transport);
 
     let mut decision = build_ai_execution_decision_response(AiExecutionDecisionResponseParts {
         decision_is_stream: spec_metadata.require_streaming,
@@ -134,6 +134,7 @@ pub(super) async fn maybe_build_local_gemini_files_decision_payload_for_candidat
         request_id: trace_id.to_string(),
         candidate_id: candidate_id.clone(),
         provider_name: transport.provider.name.clone(),
+        provider_type: transport.provider.provider_type.clone(),
         provider_id: candidate.provider_id.clone(),
         endpoint_id: candidate.endpoint_id.clone(),
         key_id: candidate.key_id.clone(),
@@ -156,8 +157,8 @@ pub(super) async fn maybe_build_local_gemini_files_decision_payload_for_candidat
             .map(str::trim)
             .filter(|value| !value.is_empty())
             .map(ToOwned::to_owned),
-        content_encoding: None,
-        request_gzip,
+        content_encoding: request_encoding.content_encoding,
+        request_gzip: request_encoding.request_gzip,
         proxy,
         transport_profile,
         timeouts: resolve_transport_execution_timeouts(&transport),
@@ -166,6 +167,10 @@ pub(super) async fn maybe_build_local_gemini_files_decision_payload_for_candidat
         report_context: Some(report_context),
         auth_context: input.auth_context.clone(),
     });
-    apply_provider_request_routing_policy_to_decision(input, &mut decision)?;
+    apply_provider_request_routing_policy_to_decision(
+        input,
+        &mut decision,
+        Some(transport.as_ref()),
+    )?;
     Ok(Some(decision))
 }

apps/aether-gateway/src/ai_serving/planner/specialized/files/support.rs

@@ -53,7 +53,9 @@ pub(super) async fn resolve_local_gemini_files_decision_input(
         state,
         auth_context,
         None,
+        decision.auth_endpoint_signature.as_deref(),
         Some(&explicit_required_capabilities),
+        &decision.model_directive_policy,
     )
     .await
     {