docs: add provider hub and model provider pages

docs/providers/openrouter.md

@@ -0,0 +1,35 @@
+---
+summary: "Use OpenRouter's unified API to access many models in Clawdbot"
+read_when:
+  - You want a single API key for many LLMs
+  - You want to run models via OpenRouter in Clawdbot
+---
+# OpenRouter
+
+OpenRouter provides a **unified API** that routes requests to many models behind a single
+endpoint and API key. It is OpenAI-compatible, so most OpenAI SDKs work by switching the base URL.
+
+## CLI setup
+
+```bash
+clawdbot onboard --auth-choice apiKey --token-provider openrouter --token "$OPENROUTER_API_KEY"
+```
+
+## Config snippet
+
+```json5
+{
+  env: { OPENROUTER_API_KEY: "sk-or-..." },
+  agents: {
+    defaults: {
+      model: { primary: "openrouter/anthropic/claude-sonnet-4-5" }
+    }
+  }
+}
+```
+
+## Notes
+
+- Model refs are `openrouter/<provider>/<model>`.
+- For more model/provider options, see [/concepts/model-providers](/concepts/model-providers).
+- OpenRouter uses a Bearer token with your API key under the hood.