diff --git a/.gitignore b/.gitignore
index d3fdee6b5..97036af72 100644
--- a/.gitignore
+++ b/.gitignore
@@ -71,3 +71,4 @@ USER.md
 
 # local tooling
 .serena/
+package-lock.json
diff --git a/src/config/types.plugins.ts b/src/config/types.plugins.ts
index 85737aa67..c2518e892 100644
--- a/src/config/types.plugins.ts
+++ b/src/config/types.plugins.ts
@@ -4,7 +4,7 @@ export type PluginEntryConfig = {
 };
 
 export type PluginSlotsConfig = {
-  /** 
+  /**
    * Select which plugin(s) own the memory slot.
    * - Single string: "memory-lancedb" - one plugin active
    * - Array: ["memory-core", "memory-lancedb"] - multiple plugins active (stackable)
diff --git a/src/plugins/slots.ts b/src/plugins/slots.ts
index bae1c1fe1..3ea639633 100644
--- a/src/plugins/slots.ts
+++ b/src/plugins/slots.ts
@@ -52,9 +52,15 @@ export function applyExclusiveSlotSelection(params: {
   };
 
   const inferredPrevSlot = prevSlot ?? defaultSlotIdForKey(slotKey);
+  // Format slot value for display (handles both string and array)
+  const formatSlotValue = (v: string | string[] | null | undefined): string => {
+    if (v === null || v === undefined) return "none";
+    if (Array.isArray(v)) return `[${v.join(", ")}]`;
+    return v;
+  };
   if (inferredPrevSlot && inferredPrevSlot !== params.selectedId) {
     warnings.push(
-      `Exclusive slot "${slotKey}" switched from "${inferredPrevSlot}" to "${params.selectedId}".`,
+      `Exclusive slot "${slotKey}" switched from "${formatSlotValue(inferredPrevSlot)}" to "${params.selectedId}".`,
     );
   }