fix(config): add missing params field to agents.list[] validation schema

The AgentConfig TypeScript type already declares params as
Record<string, unknown>, but the Zod validation schema in
AgentEntrySchema omits it. Because the schema uses .strict(),
any agents.list[] entry containing params (e.g. cacheRetention,
temperature, maxTokens) is rejected by `openclaw config validate`.

Add the params field to AgentEntrySchema to match the type definition.

Fixes #41160

src/config/zod-schema.agent-runtime.ts

@@ -757,6 +757,7 @@ export const AgentEntrySchema = z
       .strict()
       .optional(),
     sandbox: AgentSandboxSchema,
+    params: z.record(z.string(), z.unknown()).optional(),
     tools: AgentToolsSchema,
     runtime: AgentRuntimeSchema,
   })