docs: add quick setup blocks to chat providers

docs/providers/models.md

@@ -0,0 +1,33 @@
+---
+summary: "Model providers (LLMs) supported by Clawdbot"
+read_when:
+  - You want to choose a model provider
+  - You want quick setup examples for LLM auth + model selection
+---
+# Model Providers
+
+Clawdbot can use many LLM providers. Pick one, authenticate, then set the default
+model as `provider/model`.
+
+## Quick start (two steps)
+
+1) Authenticate with the provider (usually via `clawdbot onboard`).
+2) Set the default model:
+
+```json5
+{
+  agents: { defaults: { model: { primary: "anthropic/claude-opus-4-5" } } }
+}
+```
+
+## Supported providers (starter set)
+
+- [OpenAI (API + Codex)](/providers/openai)
+- [Anthropic (API + Claude CLI)](/providers/anthropic)
+- [OpenRouter](/providers/openrouter)
+- [OpenCode Zen](/providers/opencode)
+- [Z.AI](/providers/zai)
+- [GLM models](/providers/glm)
+
+For the full provider catalog (xAI, Groq, Mistral, etc.) and advanced configuration,
+see [Model providers](/concepts/model-providers).