feat(provider-routing): add OpenRouter provider routing configuration

Introduced a new `provider_routing` section in the CLI configuration to control how requests are routed across providers when using OpenRouter. This includes options for sorting providers by throughput, latency, or price, as well as allowing or ignoring specific providers, setting the order of provider attempts, and managing data collection policies. Updated relevant classes and documentation to support these features, enhancing flexibility in provider selection.

cli-config.yaml.example

@@ -20,6 +20,32 @@ model:
   # api_key: "your-key-here"  # Uncomment to set here instead of .env
   base_url: "https://openrouter.ai/api/v1"
 
+# =============================================================================
+# OpenRouter Provider Routing (only applies when using OpenRouter)
+# =============================================================================
+# Control how requests are routed across providers on OpenRouter.
+# See: https://openrouter.ai/docs/guides/routing/provider-selection
+#
+# provider_routing:
+#   # Sort strategy: "price" (default), "throughput", or "latency"
+#   # Append :nitro to model name for a shortcut to throughput sorting.
+#   sort: "throughput"
+#
+#   # Only allow these providers (provider slugs from OpenRouter)
+#   # only: ["anthropic", "google"]
+#
+#   # Skip these providers entirely
+#   # ignore: ["deepinfra", "fireworks"]
+#
+#   # Try providers in this order (overrides default load balancing)
+#   # order: ["anthropic", "google", "together"]
+#
+#   # Require providers to support all parameters in your request
+#   # require_parameters: true
+#
+#   # Data policy: "allow" (default) or "deny" to exclude providers that may store data
+#   # data_collection: "deny"
+
 # =============================================================================
 # Terminal Tool Configuration
 # =============================================================================