feat(01-01): extend EvaluationConfigSchema with ranking fields

- Add rankingEnabled: z.boolean().default(false)
- Add rankingCriteria: z.string().optional()
- Add autoRankOnComplete: z.boolean().default(false)
- All fields are optional/defaulted for backwards compatibility with existing rounds
- npm run typecheck passes cleanly

src/types/competition-configs.ts

@@ -137,6 +137,11 @@ export const EvaluationConfigSchema = z.object({
         .default('admin_decides'),
     })
     .optional(),
+
+  // Ranking (Phase 1)
+  rankingEnabled: z.boolean().default(false),
+  rankingCriteria: z.string().optional(),
+  autoRankOnComplete: z.boolean().default(false),
 })
 
 export type EvaluationConfig = z.infer<typeof EvaluationConfigSchema>