fix(system-rsc): correct slot detection in getSlots()

.changeset/four-guests-sneeze.md

@@ -0,0 +1,5 @@
+---
+"@heroui/system-rsc": minor
+---
+
+fix(system-rsc): correct slot detection in getSlots() to ensure proper slot key extraction and consistent compoundVariants behavior.

packages/core/system-rsc/src/extend-variants.js

@@ -4,22 +4,40 @@ import clsx from "clsx";
 
 import {mapPropsVariants} from "./utils";
 
+/**
+ * Extracts slot names from variant configurations.
+ * Traverses: variants -> variant groups -> variant configs -> slot names
+ * @param {Object} variants - Nested object: { variantName: { value: { slotName: "...", ... } } }
+ * @returns {Object} Map of slot names to empty strings
+ */
 function getSlots(variants) {
-  return variants
-    ? Object.values(variants)
-        .flatMap(Object.values)
-        .reduce((acc, slot) => {
-          if (typeof slot === "object" && slot !== null && !(slot instanceof String)) {
-            Object.keys(slot).forEach((key) => {
-              if (!acc.hasOwnProperty(key)) {
-                acc[key] = "";
-              }
-            });
-          }
-
-          return acc;
-        }, {})
-    : {};
+  if (!variants || typeof variants !== "object") return {};
+
+  const acc = Object.create(null);
+
+  for (const group of Object.values(variants)) {
+    if (!group || typeof group !== "object") continue;
+
+    for (const config of Object.values(group)) {
+      // Skip non-objects, arrays (which would yield numeric indices), and String objects
+      if (
+        !config ||
+        typeof config !== "object" ||
+        Array.isArray(config) ||
+        config instanceof String
+      ) {
+        continue;
+      }
+
+      for (const slotName of Object.keys(config)) {
+        if (!Object.prototype.hasOwnProperty.call(acc, slotName)) {
+          acc[slotName] = "";
+        }
+      }
+    }
+  }
+
+  return acc;
 }
 
 function getClassNamesWithProps({