docs(zai): align setup guide with runtime defaults

- remove trailing whitespace in .env.example Z.AI block
- align documented model defaults/options with current onboard/provider behavior
- keep this PR docs-focused by reverting incidental workflow edits

.env.example

@@ -70,14 +70,14 @@ PROVIDER=openrouter
 # HOST_PORT=3000
 
 # ── Z.AI GLM Coding Plan ───────────────────────────────────────
-# Z.AI provides GLM models (glm-4.5, glm-4.6, glm-4.7, glm-5).
+# Z.AI provides GLM models through OpenAI-compatible endpoints.
 # API key format: id.secret (e.g., abc123.xyz789)
-# 
+#
 # Usage:
 #   zeroclaw onboard --provider zai --api-key YOUR_ZAI_API_KEY
 #
 # Or set the environment variable:
 # ZAI_API_KEY=your-id.secret
 #
-# Available models: glm-4.5, glm-4.5-air, glm-4.6, glm-4.7, glm-5
+# Common models: glm-5, glm-4.7, glm-4-plus, glm-4-flash
 # See docs/zai-glm-setup.md for detailed configuration.