Fix task poller callback staleness and normalize filings query

lib/api.ts

@@ -153,11 +153,21 @@ export async function getLatestPortfolioInsight() {
 }
 
 export async function listFilings(query?: { ticker?: string; limit?: number }) {
+  const queryParams: {
+    ticker?: string;
+    limit?: number;
+  } = {};
+
+  if (query?.ticker?.trim()) {
+    queryParams.ticker = query.ticker.trim().toUpperCase();
+  }
+
+  if (query?.limit !== undefined) {
+    queryParams.limit = query.limit;
+  }
+
   const result = await client.api.filings.get({
-    $query: {
-      ticker: query?.ticker,
-      limit: query?.limit
-    }
+    $query: queryParams
   });
 
   return await unwrapData<{ filings: Filing[] }>(result, 'Unable to fetch filings');