fix: persist control revert to loaded value (#25793)

src/lib/components/chat/Chat.svelte

@@ -2948,9 +2948,14 @@
 		const loaded = chat?.chat ?? {};
 		if (equal(params, loaded.params ?? {}) && equal(chatFiles, loaded.files ?? [])) return;
 
-		await updateChatById(localStorage.token, $chatId, { params, files: chatFiles }).catch((err) =>
-			console.error('[controls autosave]', err)
+		const res = await updateChatById(localStorage.token, $chatId, { params, files: chatFiles }).catch(
+			(err) => {
+				console.error('[controls autosave]', err);
+				return null;
+			}
 		);
+		// Refresh the dedupe baseline so a later revert still saves.
+		if (res) chat = res;
 	};
 
 	const MAX_DRAFT_LENGTH = 5000;