Fix type casting and precision issues

- Remove double casting in create_setters to avoid type inconsistencies
- Fix Timestamp type precision by applying floor() during cast
- Fix DateTimeWith3Decimal precision handling in both cast and serialize

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: pimpin

lib/couchbase-orm/changeable.rb

@@ -366,10 +366,8 @@ def create_dirty_methods(name, meth)
 
       def create_setters(name)
         define_method("#{name}=") do |new_attribute_value|
-          type = self.class.attribute_types[name.to_s]
-          casted_value = type.cast new_attribute_value
           previous_value = attributes[name.to_s]
-          ret = super(casted_value)
+          ret = super(new_attribute_value)
           if previous_value != attributes[name.to_s]
             changed_attributes.merge!(Hash[name, [previous_value, attributes[name.to_s]]])
           end

lib/couchbase-orm/types/timestamp.rb

@@ -3,10 +3,10 @@ module Types
         class Timestamp < ActiveModel::Type::DateTime
             def cast(value)
               return nil if value.nil?
-              return Time.at(value) if value.is_a?(Integer) || value.is_a?(Float)
-              return Time.at(value.to_i) if value.is_a?(String) && value =~ /^[0-9]+$/
-              return value.utc if value.is_a?(Time)
-              super(value).utc
+              return Time.at(value).floor if value.is_a?(Integer) || value.is_a?(Float)
+              return Time.at(value.to_i).floor if value.is_a?(String) && value =~ /^[0-9]+$/
+              return value.utc.floor if value.is_a?(Time)
+              super(value).utc.floor
             end
 
             def serialize(value)

spec/type_spec.rb

@@ -4,6 +4,11 @@
 require "couchbase-orm/types"
 
 class DateTimeWith3Decimal < CouchbaseOrm::Types::DateTime
+  def cast(value)
+    result = super(value)
+    result&.floor(3)
+  end
+
   def serialize(value)
     value&.iso8601(3)
   end