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));
+}
+