feat: add Codex and OpenCode routers with multi-provider support and updated configurations

demos/llm_routing/codex_router/config.yaml

@@ -0,0 +1,38 @@
+version: v0.3.0
+
+listeners:
+  - type: model
+    name: model_listener
+    port: 12000
+
+model_providers:
+  # OpenAI Models
+  - model: openai/gpt-5-2025-08-07
+    default: true
+    access_key: $OPENAI_API_KEY
+    routing_preferences:
+      - name: code generation
+        description: generating new code snippets, functions, or boilerplate based on user prompts or requirements
+
+  - model: openai/gpt-4.1-2025-04-14
+    access_key: $OPENAI_API_KEY
+    routing_preferences:
+      - name: code understanding
+        description: understand and explain existing code snippets, functions, or libraries
+
+  # Anthropic Model
+  - model: anthropic/claude-sonnet-4-6
+    access_key: $ANTHROPIC_API_KEY
+
+  # Ollama Model (optional local fallback)
+  - model: ollama/llama3.1
+    base_url: http://host.docker.internal:11434
+
+# Model aliases for Codex sessions
+model_aliases:
+  # Default model Codex should request when launched by planoai cli-agent codex
+  arch.codex.default:
+    target: gpt-5-2025-08-07
+
+tracing:
+  random_sampling: 100