Health-system decentralization and maternal care continuity in Ghana: target-trial emulation of district-level fiscal authority effects

District-level fiscal authority is widely assumed to strengthen maternal care continuity, yet the causal claim rests on observational contrasts that are vulnerable to confounding by facility wealth and pre-existing service capacity. The design compares eight, sixteen, twenty-four and thirty-two districts across effect sizes of three, five and eight percentage points, with two thousand replications per design cell. Under a between-cluster standard deviation of 6.0, a residual standard deviation of 4.5 and an intraclass correlation of 0.64, the analysis shows that fifty-two clusters are required to detect a five-percentage-point effect at eighty per cent power. Power curves, minimum detectable effect curves, coefficient plots, scatter fits, residual diagnostics and density estimates are reported to make the design's precision transparent before field implementation. The contribution is a pre-specified, falsifiable template for evaluating fiscal decentralization effects on maternal care continuity in Ghanaian districts, together with an explicit statement of the cluster counts at which such an evaluation becomes informative.