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/parser_bitops_test.rs

@@ -0,0 +1,20 @@
+use crate::parser::NyashParser;
+use crate::ast::ASTNode;
+
+#[test]
+fn parse_bitops_and_shift_precedence() {
+    // Expression: 1 + 2 << 3 & 7
+    // Precedence: shift before add, then &: (1 + (2 << 3)) & 7
+    let code = "return 1 + 2 << 3 & 7";
+    let ast = NyashParser::parse_from_string(code).expect("parse ok");
+    // Just ensure it parses into a Program and contains a Return; deeper tree checks are optional here
+    fn has_return(n: &ASTNode) -> bool {
+        match n {
+            ASTNode::Program { statements, .. } => statements.iter().any(has_return),
+            ASTNode::Return { .. } => true,
+            _ => false,
+        }
+    }
+    assert!(has_return(&ast));
+}
+

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());
+}