fix: update perch document to support gpt-5-mini

Signed-off-by: yashodgayashan <yashodgayashan@gmail.com>

Author: yashodgayashan

docs/ai/perch-agent.mdx

@@ -85,12 +85,13 @@ Enable the Perch Agent and point it at your secret + model. The `--reuse-values`
   --reuse-values \\
   --set perchAgent.enabled=true \\
   --set perchAgent.llm.secretName=perch-agent-secret \\
-  --set perchAgent.llm.modelName=openai:gpt-5`}
+  --set perchAgent.llm.modelName=openai:gpt-5-mini`}
 </CodeBlock>
 
 :::note Supported Models
 Any `provider:model` string accepted by LangChain's `init_chat_model` works. Common picks:
 
+- `openai:gpt-5-mini` — lightweight, low-cost option for development and quick chats.
 - `openai:gpt-5` — base model, good default for development.
 - `openai:gpt-5.2-pro` — better tool-use reasoning, recommended for production.
 - `openai:gpt-5.4` — latest, highest-quality option.