fix: handle different Redis return types for num_docs field (#639)

Fix ClassCastException when retrieving document count from Redis index info.
Redis can return num_docs as either String or Long depending on version/config.

Applied robust type checking to all occurrences:
- RedisJSONKeyValueAdapter.count()
- RedisEnhancedKeyValueAdapter.count()
- RedisFluentQueryByExample (already fixed in SearchStreamImpl)

The fix handles:
- String values: parse to Long
- Number values: convert to long
- Null/unexpected: return 0L safely

This is more robust than PR #640's approach as it:
- Handles multiple Redis return types
- Avoids NullPointerException
- Prevents unnecessary String conversions
- Provides safe fallback for unexpected types

Author: bsbodden

redis-om-spring/src/main/java/com/redis/om/spring/RedisEnhancedKeyValueAdapter.java

@@ -392,7 +392,21 @@ public long count(String keyspace) {
     String indexName = indexer.getIndexName(keyspace);
     SearchOperations<String> search = modulesOperations.opsForSearch(indexName);
     var info = search.getInfo();
-    return (long) info.get("num_docs");
+    return extractNumDocs(info);
+  }
+
+  private long extractNumDocs(Map<String, Object> info) {
+    Object numDocsValue = info.get("num_docs");
+
+    // Handle different return types from Redis
+    if (numDocsValue instanceof String) {
+      return Long.parseLong((String) numDocsValue);
+    } else if (numDocsValue instanceof Number) {
+      return ((Number) numDocsValue).longValue();
+    } else {
+      // Fallback to 0 if the value is null or unexpected type
+      return 0L;
+    }
   }
 
   /*

redis-om-spring/src/main/java/com/redis/om/spring/RedisJSONKeyValueAdapter.java

@@ -7,6 +7,7 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 
@@ -346,7 +347,21 @@ public long count(String keyspace) {
     String indexName = indexer.getIndexName(keyspace);
     SearchOperations<String> search = modulesOperations.opsForSearch(indexName);
     var info = search.getInfo();
-    return (long) info.get("num_docs");
+    return extractNumDocs(info);
+  }
+
+  private long extractNumDocs(Map<String, Object> info) {
+    Object numDocsValue = info.get("num_docs");
+
+    // Handle different return types from Redis
+    if (numDocsValue instanceof String) {
+      return Long.parseLong((String) numDocsValue);
+    } else if (numDocsValue instanceof Number) {
+      return ((Number) numDocsValue).longValue();
+    } else {
+      // Fallback to 0 if the value is null or unexpected type
+      return 0L;
+    }
   }
 
   /*

redis-om-spring/src/main/java/com/redis/om/spring/search/stream/RedisFluentQueryByExample.java

@@ -271,7 +271,17 @@ public Page<R> page(Pageable pageable) {
       count = searchResult.getTotalResults();
     } else {
       var info = searchOps.getInfo();
-      count = (long) info.get("num_docs");
+      Object numDocsValue = info.get("num_docs");
+
+      // Handle different return types from Redis
+      if (numDocsValue instanceof String) {
+        count = Long.parseLong((String) numDocsValue);
+      } else if (numDocsValue instanceof Number) {
+        count = ((Number) numDocsValue).longValue();
+      } else {
+        // Fallback to 0 if the value is null or unexpected type
+        count = 0L;
+      }
     }
 
     var pageContents = searchStream.limit(pageable.getPageSize()).skip(pageable.getOffset()).collect(Collectors