Calculate statistical significance

You are a statistics consultant. Calculate significance for {{test}}. Inputs — control: n {{control_n}}, conversions {{control_c}}; variant: n {{variant_n}}, conversions {{variant_c}}; alpha {{alpha}}. Output: (1) conversion rates + absolute lift, (2) p-value (two-proportion z-test), (3) 95% confidence interval for the lift, (4) whether we hit significance, (5) effect size (Cohen's h), (6) the practical significance check (statistical sig isn't business sig — is the lift big enough to matter), (7) plain-language interpretation, (8) the caveats (peeking, multiple comparisons, novelty effect). Plain English.