refactor: Break apart monolithic configuration schema (#1977)

[skip ci]

src/config/schema/common/transition-effect.ts

@@ -0,0 +1,4 @@
+import { z } from 'zod';
+
+export const transitionEffectConfigSchema = z.enum(['none', 'slide']);
+export type TransitionEffect = z.infer<typeof transitionEffectConfigSchema>;