fix: resolve RuboCop Style/OneClassPerFile violations

.rubocop.yml

@@ -110,3 +110,11 @@ Style/StringLiteralsInInterpolation:
 # Minitest assertions
 Minitest/MultipleAssertions:
   Max: 10
+
+# Allow multiple classes/modules in extension files that patch stdlib
+# and in test files that group related test classes
+Style/OneClassPerFile:
+  Exclude:
+    - 'lib/classifier/extensions/vector.rb'
+    - 'lib/classifier/lsi.rb'
+    - 'test/**/*'

test/lsi/lsi_test.rb

@@ -691,7 +691,7 @@ def test_singular_values_populated_after_build
 
     refute_nil lsi.singular_values
     assert_instance_of Array, lsi.singular_values
-    assert(lsi.singular_values.all? { |v| v.is_a?(Numeric) })
+    assert(lsi.singular_values.all?(Numeric))
     assert_predicate lsi.singular_values.size, :positive?
   end