fix: emit OpenQASM 2 syntax for classical conditionals

CHANGELOG.md

@@ -27,6 +27,7 @@ Types of changes:
 - Fixed qubit register ranges dropping their final qubit during unrolling. Endpoints are now inclusive for gates, aliases, barriers, and measurements. Code using an exclusive upper bound must lower it by one, for example `q[0:1]` instead of `q[0:2]` to select two qubits. ([#432](https://github.com/qBraid/pyqasm/issues/432))
 - Fixed `cs` and `csdg` from `stdgates.inc` being rejected during unrolling. They now decompose to controlled phase shifts. ([#439](https://github.com/qBraid/pyqasm/issues/439))
 - Fixed Clifford+T rebasing for exact `rx`, `ry`, and `rz` rotations at multiples of π/4. These gates now decompose instead of disappearing, while angles outside the exact basis raise `RebaseError` instead of producing an incorrect result. ([#428](https://github.com/qBraid/pyqasm/issues/428))
+- Fixed the OpenQASM 2 serializer emitting OpenQASM 3 syntax for classical conditionals. `if(m==1) x q[1];` was written as a braced block and, after `unroll()`, as a per-bit `if (m[0] == true)` chain, which QASM 2 parsers such as pytket and Qiskit reject. Conditionals are now emitted as `if (creg == int) <statement>`, and `validate()` rejects branch shapes QASM 2 cannot express. ([#337](https://github.com/qBraid/pyqasm/issues/337))
 
 ### Dependencies