feat(config): add default_run_agent schema option

Add optional 'default_run_agent' field to OhMyOpenCodeConfig schema.
This field allows users to configure the default agent for the 'run' command
via oh-my-opencode.json configuration file.

- Add Zod schema: z.string().optional()
- Regenerate JSON schema for IDE support

assets/oh-my-opencode.schema.json

@@ -11,6 +11,9 @@
     "new_task_system_enabled": {
       "type": "boolean"
     },
+    "default_run_agent": {
+      "type": "string"
+    },
     "disabled_mcps": {
       "type": "array",
       "items": {

src/config/schema.ts

@@ -366,6 +366,8 @@ export const OhMyOpenCodeConfigSchema = z.object({
   $schema: z.string().optional(),
   /** Enable new task system (default: false) */
   new_task_system_enabled: z.boolean().optional(),
+  /** Default agent name for `oh-my-opencode run` (env: OPENCODE_DEFAULT_AGENT) */
+  default_run_agent: z.string().optional(),
   disabled_mcps: z.array(AnyMcpNameSchema).optional(),
   disabled_agents: z.array(BuiltinAgentNameSchema).optional(),
   disabled_skills: z.array(BuiltinSkillNameSchema).optional(),