update base-max to use sonnet 4.5

Author: charleslien

.agents/base-max.ts

@@ -6,7 +6,7 @@ import type { SecretAgentDefinition } from './types/secret-agent-definition'
 const definition: SecretAgentDefinition = {
   id: 'base-max',
   publisher,
-  ...base('anthropic/claude-sonnet-4', 'max'),
+  ...base('anthropic/claude-sonnet-4.5', 'max'),
   spawnableAgents: [
     'file-explorer',
     'researcher-web-gpt-5',