fix: replace remaining .filter() calls with for loops in RSS Reader

QuickJS doesn't reliably support Array.prototype.filter(). Replace all
remaining .filter() calls in filterByKeyword() and filterByDate() with
manual for loops for full QuickJS compatibility.

nodes/rss/rss-reader.js

@@ -2,7 +2,7 @@
  * @node rss-reader
  * @name RSS Reader
  * @category data
- * @version 1.1.5
+ * @version 1.1.6
  * @description Read and parse RSS/Atom feeds with optional filtering by keyword, date, or count. Supports stateful new item detection.
  * @icon rss
  */
@@ -506,11 +506,16 @@ function filterByKeyword(items, keyword) {
     if (!keyword) return items;
 
     var lowerKeyword = keyword.toLowerCase();
-    return items.filter(function(item) {
+    var result = [];
+    for (var i = 0; i < items.length; i++) {
+        var item = items[i];
         var title = (item.title || '').toLowerCase();
         var description = (item.description || '').toLowerCase();
-        return title.indexOf(lowerKeyword) !== -1 || description.indexOf(lowerKeyword) !== -1;
-    });
+        if (title.indexOf(lowerKeyword) !== -1 || description.indexOf(lowerKeyword) !== -1) {
+            result.push(item);
+        }
+    }
+    return result;
 }
 
 /**
@@ -525,10 +530,15 @@ function filterByDate(items, newerThanStr) {
         return items;
     }
 
-    return items.filter(function(item) {
+    var result = [];
+    for (var i = 0; i < items.length; i++) {
+        var item = items[i];
         var itemDate = parseDate(item.pubDate);
-        return itemDate > threshold;
-    });
+        if (itemDate > threshold) {
+            result.push(item);
+        }
+    }
+    return result;
 }
 
 /**