feat: add Object.same static method for reliable built-in equality

Introduce a new static method `Object.same(obj1, obj2)` that exposes the VM's
built-in equality semantics (`wrenValuesEqual`) directly, bypassing any
user-defined `==` overrides. This required creating a dedicated metaclass for
Object (subclass of Class) to host the static method without polluting every
class with a `same` method. The implementation wires up a new `Object metaclass`
in the core initialization sequence, adjusts the class hierarchy setup order,
and adds comprehensive tests covering value types, identity comparison, and
verification that `Object.same` ignores custom `==` operators.

test/core/object/same.wren

@@ -0,0 +1,40 @@
+// Value types compare by value.
+IO.print(Object.same(true, true)) // expect: true
+IO.print(Object.same(true, false)) // expect: false
+
+IO.print(Object.same(null, null)) // expect: true
+
+IO.print(Object.same(1 + 2, 2 + 1)) // expect: true
+IO.print(Object.same(1 + 2, 2 + 2)) // expect: false
+
+IO.print(Object.same(1..2, 1..2)) // expect: true
+IO.print(Object.same(1..2, 1..3)) // expect: false
+
+IO.print(Object.same("ab", "a" + "b")) // expect: true
+IO.print(Object.same("ab", "a" + "c")) // expect: false
+
+// Different types are never the same.
+IO.print(Object.same(null, false)) // expect: false
+IO.print(Object.same(true, 2)) // expect: false
+IO.print(Object.same(1..2, 2)) // expect: false
+IO.print(Object.same("1", 1)) // expect: false
+
+// Classes compare by identity.
+IO.print(Object.same(Bool, Num)) // expect: false
+IO.print(Object.same(Bool, Bool)) // expect: true
+
+// Other types compare by identity.
+class Foo {}
+
+var foo = new Foo
+IO.print(Object.same(foo, foo)) // expect: true
+IO.print(Object.same(foo, new Foo)) // expect: false
+
+// Ignores == operators.
+class Bar {
+  ==(other) { true }
+}
+
+var bar = new Bar
+IO.print(Object.same(bar, bar)) // expect: true
+IO.print(Object.same(bar, new Bar)) // expect: false