feat(litellm): front z.ai GLM cloud models through the gateway

Adds explicit gateway entries for the four z.ai GLM models (glm-5.1,
glm-5-turbo, glm-4.7, glm-4.5-air) routed to api.z.ai with Z_AI_API_KEY,
plus the compose env passthrough + .env.example doc. Explicit entries
win over the llama-swap wildcard (distinct IDs, no collision). Extends
the gateway's unified logging to cloud inference, not just local
vLLM/llama-swap.

Cost note: paid API — only gateway-keyed callers reach these, but calls
spend z.ai credits (documented in config + compose comments).

stacks/litellm/conf/config.yaml

@@ -45,6 +45,32 @@ model_list:
     model_info:
       mode: rerank
 
+  # --- z.ai GLM (cloud API) — fronted for unified logging across local
+  #     + cloud inference. Explicit entries, so they win over the "*"
+  #     wildcard below (no collision with llama-swap's glm4.7-flash etc.
+  #     — different model IDs). NOTE: paid API; only gateway-keyed callers
+  #     can reach these, but they DO spend z.ai credits. Key in .env. ---
+  - model_name: glm-5.1
+    litellm_params:
+      model: openai/glm-5.1
+      api_base: https://api.z.ai/api/coding/paas/v4
+      api_key: os.environ/Z_AI_API_KEY
+  - model_name: glm-5-turbo
+    litellm_params:
+      model: openai/glm-5-turbo
+      api_base: https://api.z.ai/api/coding/paas/v4
+      api_key: os.environ/Z_AI_API_KEY
+  - model_name: glm-4.7
+    litellm_params:
+      model: openai/glm-4.7
+      api_base: https://api.z.ai/api/coding/paas/v4
+      api_key: os.environ/Z_AI_API_KEY
+  - model_name: glm-4.5-air
+    litellm_params:
+      model: openai/glm-4.5-air
+      api_base: https://api.z.ai/api/coding/paas/v4
+      api_key: os.environ/Z_AI_API_KEY
+
   # --- llama-swap passthrough (the swappable generative LLM zoo on
   #     ana-ml2:9292) ---
   # Wildcard: any model name NOT matched by an exact entry above routes to