feat(zai): add GLM-5V-Turbo support for coding plan (#9907)

- Add glm-5v-turbo to OpenRouter, Nous, and native Z.AI model lists
- Add glm-5v context length entry (200K tokens) to model metadata
- Update Z.AI endpoint probe to try multiple candidate models per
  endpoint (glm-5.1, glm-5v-turbo, glm-4.7) — fixes detection for
  newer coding plan accounts that lack older models
- Add zai to _PROVIDER_VISION_MODELS so auxiliary vision tasks
  (vision_analyze, browser screenshots) route through 5v

Fixes #9888

agent/auxiliary_client.py

@@ -112,6 +112,7 @@ _API_KEY_PROVIDER_AUX_MODELS: Dict[str, str] = {
 # "exotic provider" branch checks this before falling back to the main model.
 _PROVIDER_VISION_MODELS: Dict[str, str] = {
     "xiaomi": "mimo-v2-omni",
+    "zai": "glm-5v-turbo",
 }
 
 # OpenRouter app attribution headers