refactor: Break apart monolithic configuration schema (#1977)

[skip ci]

src/config/schema/conditions/custom/key.ts

@@ -0,0 +1,11 @@
+import { z } from 'zod';
+
+export const keyConditionSchema = z.object({
+  condition: z.literal('key'),
+  key: z.string(),
+  state: z.enum(['down', 'up']).optional(),
+  ctrl: z.boolean().optional(),
+  shift: z.boolean().optional(),
+  alt: z.boolean().optional(),
+  meta: z.boolean().optional(),
+});