fix: skip thinking param injection for GLM models in sisyphus-junior (#2967)

GLM-5 has native reasoning built-in. Injecting thinking: {type: 'enabled'}
causes a param conflict (400 error). Add isGlmModel() check to return base
config without thinking/reasoningEffort for GLM models.

- Add isGlmModel() helper to types.ts
- Early return in createSisyphusJuniorAgentWithOverrides for GLM models
- Add tests for isGlmModel and GLM reasoning config behavior

src/agents/types.ts

@@ -96,6 +96,11 @@ export function isMiniMaxModel(model: string): boolean {
   return modelName.includes("minimax");
 }
 
+export function isGlmModel(model: string): boolean {
+  const modelName = extractModelName(model).toLowerCase();
+  return modelName.includes("glm");
+}
+
 export function isGeminiModel(model: string): boolean {
   if (GEMINI_PROVIDERS.some((prefix) => model.startsWith(prefix))) return true;