Allow script arrays to hold any value type, add script engine tests, archive old rpg code

Remove the per-array type category so arrays can mix types like structs.
Add 13 passing and 125 expected-failure duskscript test fixtures with a
table-driven runner. Also includes the in-progress entity/physics and
archive moves from the working tree.

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

test/duskscript/assets/pass_strings.ds

@@ -0,0 +1,131 @@
+var s = "Hello, World";
+
+// Length and indexing
+assert(len(s) == 12);
+assert(len("") == 0);
+assert(s[0] == "H");
+assert(s[11] == "d");
+assert(s[4] == "o");
+
+// Concatenation, everything turns into text next to a string
+assert("a" + "b" == "ab");
+assert("" + "" == "");
+assert("n=" + 5 == "n=5");
+assert(5 + "n" == "5n");
+assert("v" + 1.5 == "v1.5");
+assert("b=" + true == "b=true");
+assert("b=" + false == "b=false");
+assert("x=" + null == "x=null");
+assert("x=" + undefined == "x=undefined");
+assert("a" + 1 + 2 == "a12");
+assert(1 + 2 + "a" == "3a");
+assert("arr " + [1, 2] == "arr [1, 2]");
+assert("arr " + ["a", 1] == "arr [\"a\", 1]");
+
+// Equality compares text, not identity
+assert("abc" == "abc");
+assert("abc" != "abd");
+assert("abc" != "ab");
+assert("" == "");
+assert("a" + "bc" == "ab" + "c");
+assert("1" != 1);
+
+// Case
+assert(upcase("abc DEF 123") == "ABC DEF 123");
+assert(downcase("ABC def 123") == "abc def 123");
+assert(upcase("") == "");
+
+// Trim
+assert(trim("  hi  ") == "hi");
+assert(ltrim("  hi  ") == "hi  ");
+assert(rtrim("  hi  ") == "  hi");
+assert(trim("hi") == "hi");
+assert(trim("   ") == "");
+
+// Searching
+assert(contains(s, "World"));
+assert(!contains(s, "world"));
+assert(contains(s, ""));
+assert(strindex(s, "o") == 4);
+assert(strindex(s, "World") == 7);
+assert(strindex(s, "zzz") == -1);
+assert(startswith(s, "Hello"));
+assert(!startswith(s, "World"));
+assert(startswith(s, ""));
+assert(startswith(s, s));
+assert(!startswith("ab", "abc"));
+assert(endswith(s, "World"));
+assert(!endswith(s, "Hello"));
+assert(endswith(s, s));
+assert(!endswith("bc", "abc"));
+assert(indexof("hello", "l") == 2);
+assert(lastindexof("hello", "l") == 3);
+assert(indexof("hello", "z") == -1);
+
+// Comparing helpers
+assert(stringequals("a", "a"));
+assert(!stringequals("a", "A"));
+assert(stringequalsinsensitive("a", "A"));
+assert(stringequalsinsensitive("Hello", "hELLO"));
+assert(!stringequalsinsensitive("Hello", "Hell"));
+
+// Slicing
+assert(subarr("abcdef", 2) == "cdef");
+assert(subarr("abcdef", 1, 4) == "bcd");
+assert(subarr("abcdef", 0, 0) == "");
+assert(subarr("abcdef", 6) == "");
+assert(subarr("abcdef", 0, 6) == "abcdef");
+
+// Split and join
+var parts = split("a,b,c", ",");
+assert(len(parts) == 3);
+assert(parts[0] == "a");
+assert(parts[2] == "c");
+assert(join(parts, "-") == "a-b-c");
+assert(len(split("abc", "")) == 3);
+assert(split("abc", "")[1] == "b");
+assert(len(split("abc", ",")) == 1);
+assert(len(split("a,,b", ",")) == 3);
+assert(split("a,,b", ",")[1] == "");
+assert(len(split(",", ",")) == 2);
+assert(join([], ",") == "");
+assert(join([1, "b", true, null], "|") == "1|b|true|null");
+assert(join(["x"], ",") == "x");
+assert(join(split("a--b--c", "--"), "+") == "a+b+c");
+
+// Chars
+assert(chr(65) == "A");
+assert(chr(97) == "a");
+assert(len(chr(255)) == 1);
+
+// Escapes
+assert(len("a\nb") == 3);
+assert(len("a\tb") == 3);
+assert(len("\\") == 1);
+assert(len("\"") == 1);
+assert(len('it\'s') == 4);
+assert("a\\b"[1] == "\\");
+
+// Iterating
+var total = "";
+foreach(var c : "abc") {
+  total = c + total;
+}
+assert(total == "cba");
+
+// Strings are values: the original is untouched by what was derived from it
+var original = "keep";
+var changed = upcase(original);
+assert(original == "keep");
+assert(changed == "KEEP");
+
+// Truthiness
+assert("a");
+assert(!"");
+
+// Long-ish string built in a loop
+var built = "";
+for(var i = 0; i < 100; i++) {
+  built = built + "x";
+}
+assert(len(built) == 100);