fix(test): fix test case for table deletion and optimize code

ts/00_commitinfo_data.ts

@@ -1,8 +1,8 @@
 /**
- * autocreated commitinfo by @pushrocks/commitinfo
+ * autocreated commitinfo by @push.rocks/commitinfo
  */
 export const commitinfo = {
   name: '@push.rocks/smartclickhouse',
-  version: '2.0.17',
+  version: '2.0.18',
   description: 'A TypeScript-based ODM for ClickHouse databases that supports creating, managing, and querying tables with a focus on handling time-series data.'
 }

ts/smartclickhouse.classes.timedatatable.ts

@@ -270,6 +270,7 @@ export class TimeDataTable {
     return new plugins.smartrx.rxjs.Observable((observer) => {
       const pollInterval = 1000; // Poll every 1 second
       let lastTimestamp: number;
+      let intervalId: NodeJS.Timeout;
 
       const fetchLastEntryTimestamp = async () => {
         const lastEntry = await this.smartClickHouseDbRef.clickhouseHttpClient.queryPromise(`
@@ -292,13 +293,13 @@ export class TimeDataTable {
 
       const startPolling = async () => {
         await fetchLastEntryTimestamp();
-        const intervalId = setInterval(fetchNewEntries, pollInterval);
-
-        // Cleanup on unsubscribe
-        return () => clearInterval(intervalId);
+        intervalId = setInterval(fetchNewEntries, pollInterval);
       };
 
       startPolling().catch((err) => observer.error(err));
+
+      // Cleanup on unsubscribe
+      return () => clearInterval(intervalId);
     });
   }
 }