Circuit Equivalence Checker

Paste two circuits as OpenQASM 3. Each is turned into its unitary matrix (one simulation per basis state) and compared with the phase-invariant process fidelity |Tr(V†U)|²/d² — the same measure the spec-based verifier uses for a unitary target, here applied circuit-to-circuit. Global phase is ignored: two circuits that differ only by an overall e^{iφ} are equivalent. Both circuits must have the same qubit count and be at most 10 qubits wide — this is a dense 2^n × 2^n computation, not a symbolic prover.