nx_opt_eqsat_pass_gate.nx

nx_opt_eqsat_pass_gate.nx -- proves opt_eqsat_pass REWRITES REAL IR, and that it reaches an expression the shipping pipeline structurally cannot. THE MONEY TOOTH is a head-to-head on ONE function: build `x ^ x` where x is a runtime parameter, run the INCUMBENT opt_const_fold first and require it to fold NOTHING (it needs both operands constant, so it cannot see this), then run opt_eqsat_pass and require it to fold exactly one instruction to the constant 0. A pass that merely duplicated the incumbent would fail that pair. WHY THIS IS NOT A STUB CARRYING A CONTRACT NAME: the flip law says a completion signal keyed on a symbol rewards writing the symbol. So this gate does not ask whether opt_eqsat_pass EXISTS -- it asks whether a Value that was an XOR instruction is a CONSTANT afterwards, and whether the number the incumbent folded on the same input was zero. Those are properties of the program, not the name. license_tier: ORIGINAL expect_exit: 0