tests: add parser/vm bitops tests; docs: update cheatsheet and language guide for bitwise ops and shift; note Arrow(>>) removal

- Add src/tests/parser_bitops_test.rs and vm_bitops_test.rs
- Update tokenizer unit test to expect SHIFT_RIGHT
- Update quick-reference and language guide to document &,|,^,<<,>> and Arrow deprecation

Known: one unrelated test failing (consolebox println TLV vs typebox) pre-existing.

src/tests/vm_bitops_test.rs

@@ -0,0 +1,25 @@
+use crate::parser::NyashParser;
+use crate::interpreter::NyashInterpreter;
+
+#[test]
+fn vm_exec_bitwise_and_shift() {
+    let code = r#"
+        return (5 & 3) + (5 | 2) + (5 ^ 1) + (1 << 5) + (32 >> 3)
+    "#;
+    let ast = NyashParser::parse_from_string(code).expect("parse ok");
+    let mut interp = NyashInterpreter::new();
+    let out = interp.execute(ast).expect("exec ok");
+    assert_eq!(out.to_string_box().value, "48");
+}
+
+#[test]
+fn vm_exec_shift_masking() {
+    // 1 << 100 should mask to 1 << (100 & 63) = 1 << 36
+    let code = r#" return 1 << 100 "#;
+    let ast = NyashParser::parse_from_string(code).expect("parse ok");
+    let mut interp = NyashInterpreter::new();
+    let out = interp.execute(ast).expect("exec ok");
+    // compute expected as i64
+    let expected = (1_i64 as i64).wrapping_shl((100_u32) & 63);
+    assert_eq!(out.to_string_box().value, expected.to_string());
+}