fix(athena): enforce strict schema validation for council members

Add .strict() to CouncilMemberSchema to reject unknown fields like temperature. Remove unused Zod-inferred type exports. Add test verifying unknown fields are rejected.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/config/schema/athena.ts

@@ -16,7 +16,7 @@ export const CouncilMemberSchema = z.object({
   model: ModelStringSchema,
   variant: z.string().optional(),
   name: z.string().optional(),
-})
+}).strict()
 
 export const CouncilConfigSchema = z.object({
   members: z.array(CouncilMemberSchema).min(2),
@@ -26,7 +26,3 @@ export const AthenaConfigSchema = z.object({
   model: z.string().optional(),
   council: CouncilConfigSchema,
 })
-
-export type CouncilMemberSchemaType = z.infer<typeof CouncilMemberSchema>
-export type CouncilConfigSchemaType = z.infer<typeof CouncilConfigSchema>
-export type AthenaConfigSchemaType = z.infer<typeof AthenaConfigSchema>