feat(ai): Add zAI provider support

- Add 'zai' as a KnownProvider type
- Add ZAI_API_KEY environment variable mapping
- Generate 4 zAI models (glm-4.5-air, glm-4.5v, etc.) using anthropic-messages API
- Add comprehensive test coverage for zAI provider in generate.test.ts and empty.test.ts
- Models support reasoning/thinking capabilities and tool calling

packages/ai/src/generate.ts

@@ -106,6 +106,7 @@ export function getApiKey(provider: any): string | undefined {
 		cerebras: "CEREBRAS_API_KEY",
 		xai: "XAI_API_KEY",
 		openrouter: "OPENROUTER_API_KEY",
+		zai: "ZAI_API_KEY",
 	};
 
 	const envVar = envMap[provider];