feat: add tri-state support for disable-image-generation configuration

- Introduced `DisableImageGenerationMode` with support for `false`, `true`, and `chat` values.
- Updated payload handling to preserve `image_generation` on images endpoints when `chat` mode is enabled.
- Modified OpenAI image handlers (`ImagesGenerations`, `ImagesEdits`) to respect tri-state logic.
- Added unit tests for `DisableImageGenerationMode` behavior and endpoint-specific handling.
- Enhanced configuration diff logging to support `DisableImageGenerationMode`.

sdk/api/handlers/handlers.go

@@ -198,9 +198,14 @@ func requestExecutionMetadata(ctx context.Context) map[string]any {
 	// Idempotency-Key is an optional client-supplied header used to correlate retries.
 	// Only include it if the client explicitly provides it.
 	key := ""
+	requestPath := ""
 	if ctx != nil {
 		if ginCtx, ok := ctx.Value("gin").(*gin.Context); ok && ginCtx != nil && ginCtx.Request != nil {
 			key = strings.TrimSpace(ginCtx.GetHeader("Idempotency-Key"))
+			requestPath = strings.TrimSpace(ginCtx.FullPath())
+			if requestPath == "" && ginCtx.Request.URL != nil {
+				requestPath = strings.TrimSpace(ginCtx.Request.URL.Path)
+			}
 		}
 	}
 
@@ -208,6 +213,9 @@ func requestExecutionMetadata(ctx context.Context) map[string]any {
 	if key != "" {
 		meta[idempotencyKeyMetadataKey] = key
 	}
+	if requestPath != "" {
+		meta[coreexecutor.RequestPathMetadataKey] = requestPath
+	}
 	if pinnedAuthID := pinnedAuthIDFromContext(ctx); pinnedAuthID != "" {
 		meta[coreexecutor.PinnedAuthMetadataKey] = pinnedAuthID
 	}