feat(gateway): harden provider request execution

Preserve exact request payloads and model client surface and API operation explicitly.

Add Anthropic compatibility profiles, bounded stream commitment, and scoped OAuth retry behavior across provider transports.

crates/aether-ai/serving/src/lib.rs

@@ -14,6 +14,7 @@ pub mod decision_payload;
 pub mod dto;
 pub mod execution_path;
 pub mod failure_diagnostic;
+pub mod payload_fidelity;
 pub mod plan_payload;
 pub mod ports;
 pub mod ranking_metadata;
@@ -52,7 +53,8 @@ pub use aether_pool_core::{
     REQUEST_FAILURE_PENALTY, UNSCHEDULABLE_SCORE_CAP,
 };
 pub use attempt_loop::{
-    run_ai_attempt_loop, AiAttemptLoopOutcome, AiAttemptLoopPort, AiExecutionAttempt,
+    run_ai_attempt_loop, AiAttemptExecutionOutcome, AiAttemptLoopOutcome, AiAttemptLoopPort,
+    AiAttemptRetryScope, AiExecutionAttempt,
 };
 pub use attempt_plan::{
     build_ai_execution_decision_from_plan, build_ai_execution_plan_from_decision,
@@ -106,7 +108,7 @@ pub use decision_payload::{
     AiExecutionDecisionResponseParts,
 };
 pub use dto::{
-    augment_sync_report_context, generic_decision_missing_exact_provider_request,
+    augment_sync_report_context, generic_decision_missing_exact_provider_request, AdaptationMode,
     AiExecutionDecision, AiExecutionPlanPayload, AiRequestGzipPolicy, AiStreamAttempt,
     AiSyncAttempt, ConversionMode, ExecutionStrategy,
 };
@@ -116,6 +118,7 @@ pub use execution_path::{
     AiSyncExecutionPathPort, AiSyncExecutionStep, DEFAULT_STREAM_EXECUTION_STEPS,
 };
 pub use failure_diagnostic::{CandidateFailureDiagnostic, CandidateFailureDiagnosticKind};
+pub use payload_fidelity::OriginalRequestPayload;
 pub use plan_payload::{
     build_ai_stream_execution_plan_payload, build_ai_sync_execution_plan_payload,
 };