Update release note prompt and AI model

Clarifies the release note prompt to require strict output format without wrapping the result in a code block. Also updates the release publish workflow to use `google/gemma-4-26b-a4b-it:free` instead of the previous OpenAI model endpoint setting.

Author: MliKiowa

.github/prompt/release_note_prompt.txt

@@ -24,7 +24,7 @@
 - **控制数量**：最终保持 5-15 条更新要点
 - **保留 commit hash**：每条末尾附上短 hash，格式 `(a1b2c3d)`
 
-## 输出模板 - 必须严格遵守以下格式
+## 输出模板 - 必须严格遵守以下格式，不要使用代码区域包裹
 
 ```
 # {VERSION}

.github/workflows/release-publish.yml

@@ -12,7 +12,7 @@ permissions: write-all
 
 env:
   OPENAI_API_URL: https://openrouter.ai/api/v1/chat/completions
-  OPENAI_MODEL: "z-ai/glm-4.5-air:free"
+  OPENAI_MODEL: "google/gemma-4-26b-a4b-it:free"
   RELEASE_NAME: "NapCat"
 
 jobs: