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.

tests/test_codex_execution_paths.py

@@ -148,6 +148,7 @@ def test_gateway_run_agent_codex_path_handles_internal_401_refresh(monkeypatch):
     runner._ephemeral_system_prompt = ""
     runner._prefill_messages = []
     runner._reasoning_config = None
+    runner._provider_routing = {}
     runner._running_agents = {}
     from unittest.mock import MagicMock, AsyncMock
     runner.hooks = MagicMock()