test(image-generation): tighten zhipu provider coverage

docs/configuration.md

@@ -1195,7 +1195,7 @@ If you want to always use the local conversion, you can force it using:
 
 ## Image Generation
 
-Image generation is configured under `tools.imageGeneration` and uses provider credentials from `providers.openrouter` or `providers.aihubmix`.
+Image generation is configured under `tools.imageGeneration` and uses credentials from the selected provider's `providers.<name>` block.
 
 See [Image Generation](./image-generation.md) for WebUI usage, provider examples, artifact storage, and troubleshooting.
 

docs/image-generation.md

@@ -255,7 +255,7 @@ Supported aspect ratios: `1:1`, `16:9`, `9:16`, `3:4`, `4:3`. Sizes can be speci
 {
   "providers": {
     "zhipu": {
-      "apiKey": "${ZHIPU_API_KEY}"
+      "apiKey": "${ZAI_API_KEY}"
     }
   },
   "tools": {
@@ -328,4 +328,3 @@ Use the reference image. Keep the same robot and composition, change the palette
 | AIHubMix says `Incorrect model ID` | Use `model: "gpt-image-2-free"`; nanobot expands it to the required `openai/gpt-image-2-free` model path internally |
 | Generation times out | Try a smaller/default image size, set AIHubMix `extraBody.quality` to `"low"`, or retry later |
 | Reference image rejected | Reference image paths must be inside the workspace or nanobot media directory and must be valid image files |
-