use optional instead of required for tdd config for backwards compatibility

assets/oh-my-opencode.schema.json

@@ -4267,9 +4267,6 @@
           "type": "boolean"
         }
       },
-      "required": [
-        "tdd"
-      ],
       "additionalProperties": false
     },
     "comment_checker": {

src/config/schema/sisyphus-agent.ts

@@ -5,7 +5,7 @@ export const SisyphusAgentConfigSchema = z.object({
   default_builder_enabled: z.boolean().optional(),
   planner_enabled: z.boolean().optional(),
   replace_plan: z.boolean().optional(),
-  tdd: z.boolean().default(true),
+  tdd: z.boolean().default(true).optional(),
 })
 
 export type SisyphusAgentConfig = z.infer<typeof SisyphusAgentConfigSchema>