nx_plane_repair_gate.nx

nx_plane_repair_gate.nx -- proves nx_plane_repair actually repairs, on a DELIBERATELY DAMAGED plane. ★WHY THIS GATE HAD TO EXIST BEFORE THE TOOL COULD BE TRUSTED. nx_plane_repair shipped with only its NO-OP and REFUSAL paths exercised (a healthy plane declines correctly). The path that actually writes -- the one that permanently accepts data loss and rewrites the ecosystem's ledger -- was CODE-REVIEWED, NOT MEASURED. This whole workstream exists to delete exactly that distinction, so leaving it would have been the largest hypocrisy in it. ★THE FIXTURE IS THE HARD PART, and it is why this could not be tested earlier: `sts_seed` ALWAYS writes a correct q:n, so the damage it repairs is unreachable through the normal writer. The gate therefore builds the damaged plane from the RAW store primitives -- ss_add of 5 real rows, then a q:n that LIES and says 8. That reproduces the exact live shape (declared > reachable) without waiting for a real outage. It forks the REAL promoted elf rather than calling a library, so what is proven is the artifact that actually runs. license_tier: ORIGINAL expect_exit: 0