feat: implement Z.AI endpoint detection for API key validation

Added functionality to detect the appropriate Z.AI endpoint based on the provided API key, accommodating different billing plans and regions. The setup process now probes available endpoints and updates the configuration accordingly, enhancing user experience and reducing potential billing errors. Updated the setup model provider function to integrate this new detection logic.

hermes_cli/auth.py

@@ -138,6 +138,59 @@ PROVIDER_REGISTRY: Dict[str, ProviderConfig] = {
 }
 
 
+# =============================================================================
+# Z.AI Endpoint Detection
+# =============================================================================
+
+# Z.AI has separate billing for general vs coding plans, and global vs China
+# endpoints.  A key that works on one may return "Insufficient balance" on
+# another.  We probe at setup time and store the working endpoint.
+
+ZAI_ENDPOINTS = [
+    # (id, base_url, default_model, label)
+    ("global",        "https://api.z.ai/api/paas/v4",        "glm-5",   "Global"),
+    ("cn",            "https://open.bigmodel.cn/api/paas/v4", "glm-5",   "China"),
+    ("coding-global", "https://api.z.ai/api/coding/paas/v4",  "glm-4.7", "Global (Coding Plan)"),
+    ("coding-cn",     "https://open.bigmodel.cn/api/coding/paas/v4", "glm-4.7", "China (Coding Plan)"),
+]
+
+
+def detect_zai_endpoint(api_key: str, timeout: float = 8.0) -> Optional[Dict[str, str]]:
+    """Probe z.ai endpoints to find one that accepts this API key.
+
+    Returns {"id": ..., "base_url": ..., "model": ..., "label": ...} for the
+    first working endpoint, or None if all fail.
+    """
+    for ep_id, base_url, model, label in ZAI_ENDPOINTS:
+        try:
+            resp = httpx.post(
+                f"{base_url}/chat/completions",
+                headers={
+                    "Authorization": f"Bearer {api_key}",
+                    "Content-Type": "application/json",
+                },
+                json={
+                    "model": model,
+                    "stream": False,
+                    "max_tokens": 1,
+                    "messages": [{"role": "user", "content": "ping"}],
+                },
+                timeout=timeout,
+            )
+            if resp.status_code == 200:
+                logger.debug("Z.AI endpoint probe: %s (%s) OK", ep_id, base_url)
+                return {
+                    "id": ep_id,
+                    "base_url": base_url,
+                    "model": model,
+                    "label": label,
+                }
+            logger.debug("Z.AI endpoint probe: %s returned %s", ep_id, resp.status_code)
+        except Exception as exc:
+            logger.debug("Z.AI endpoint probe: %s failed: %s", ep_id, exc)
+    return None
+
+
 # =============================================================================
 # Error Types
 # =============================================================================