Fix duplicate field in School interface and update event panel description in design documentation. Adjusted reviewed phase details for clarity and accuracy.

src/HSchool.Client/src/net/api.ts

@@ -10,7 +10,6 @@ export interface School {
   readonly gameTime: string;
   readonly running: boolean;
   readonly speedIndex: number;
-  readonly speedIndex: number;
   readonly modIds?: readonly string[];
   /** Roster generator seed. Independent of `id`; share it to recreate the same people. */
   readonly seed: number;