fix: Harden instance rename against interleaving and lost unwinds

adminsite/app/(customer)/instances/[id]/page.tsx

@@ -213,7 +213,15 @@ export default function InstancePage() {
                             The instance name is where its address comes from. Renaming moves it to a new address and releases the old
                             one, so saved links and bookmarks to it stop working.
                         </p>
+                        {/*
+                         * Keyed on the instance: this element stays mounted
+                         * across a navigation between two instance pages, so
+                         * without a key the success note and the typed name
+                         * from one instance surface on the next.
+                         */}
                         <RenamePanel
+                            key={instance.instance_id}
+                            movesHost
                             currentName={instance.name}
                             currentSlug={instance.slug ?? ""}
                             onRename={async (name) => {

adminsite/app/(staff)/staff/instances/[id]/page.tsx

@@ -87,7 +87,14 @@ export default function StaffInstancePage() {
              * hours.
              */}
             <Panel title="Name" meta={data.instance.deployment === "cloud" ? "Moves the address" : "Label only"}>
+                {/*
+                 * Keyed on the instance so a success note cannot follow staff
+                 * from one instance page to the next — the element stays
+                 * mounted across that navigation.
+                 */}
                 <RenamePanel
+                    key={data.instance.instance_id}
+                    movesHost={data.instance.deployment === "cloud" && !data.instance.placeholder}
                     currentName={data.instance.name}
                     currentSlug={data.instance.slug ?? ""}
                     onRename={async (name) => {