grammar: introduce bitwise ops & shifts; retire legacy >> ARROW

- Tokenizer: add tokens for << >> & | ^ (SHIFT_LEFT/RIGHT, BIT_AND/OR/XOR); keep ||, &&, |>
- Parser: precedence layers for bit ops (| ^ &) and shift (<< >>); remove >> Arrow production
- AST: add BitAnd/BitOr/BitXor/Shr with Display
- MIR builder: map bit ops and Shr to MIR BinaryOp
- Interpreter: implement integer-only bit ops and shifts, mask shift count to 0..63

Compatibility: legacy >> Arrow removed from parser; use |> for pipeline.

src/mir/builder/ops.rs

@@ -115,6 +115,10 @@ impl super::MirBuilder {
             BinaryOperator::Divide => Ok(BinaryOpType::Arithmetic(BinaryOp::Div)),
             BinaryOperator::Modulo => Ok(BinaryOpType::Arithmetic(BinaryOp::Mod)),
             BinaryOperator::Shl => Ok(BinaryOpType::Arithmetic(BinaryOp::Shl)),
+            BinaryOperator::Shr => Ok(BinaryOpType::Arithmetic(BinaryOp::Shr)),
+            BinaryOperator::BitAnd => Ok(BinaryOpType::Arithmetic(BinaryOp::BitAnd)),
+            BinaryOperator::BitOr => Ok(BinaryOpType::Arithmetic(BinaryOp::BitOr)),
+            BinaryOperator::BitXor => Ok(BinaryOpType::Arithmetic(BinaryOp::BitXor)),
             BinaryOperator::Equal => Ok(BinaryOpType::Comparison(CompareOp::Eq)),
             BinaryOperator::NotEqual => Ok(BinaryOpType::Comparison(CompareOp::Ne)),
             BinaryOperator::Less => Ok(BinaryOpType::Comparison(CompareOp::Lt)),