Added character as a first class object. Stepped through a run; it all works.

src/c/payloads/character.h

@@ -0,0 +1,39 @@
+/**
+ *  payloads/character.h
+ *
+ *  A character object.
+ *
+ *  Note that, instead of instantiating actual character objects, it would be
+ *  possible to reserve one special page index, outside the normal page range,
+ *  possibly even page 0, such that a character would be represented by a
+ *  pso_pointer {node, special_page, character_code}. The special page wouldn't
+ *  actually have to exist. This wouldn't prevent `nil` being 'the object at
+ *  {n, 0, 0}, since the UTF character with the index 0 is NULL, which feels
+ *  entirely compatible. UTF 1 is 'Start of heading', which is not used by
+ *  anything I'm aware of these days, and is canonically not NULL, so I don't
+ *  see why we should not continue to treat {n, 0, 1} as `t`.
+ *
+ *  (c) 2026 Simon Brooke <simon@journeyman.cc>
+ *  Licensed under GPL version 2.0, or, at your option, any later version.
+ */
+
+#ifndef __psse_payloads_character_h
+#define __psse_payloads_character_h
+/*
+ * wide characters
+ */
+#include <wchar.h>
+#include <wctype.h>
+
+
+#define CHARTAG "CHR"
+#define CHARTV  5392451
+
+/**
+ * @brief a single character, as returned by the reader.
+ */
+struct character_payload {
+    wchar_t character;
+};
+
+#endif