add Redis session affinity demos (Docker Compose and Kubernetes)

demos/llm_routing/session_affinity_redis/config.yaml

@@ -0,0 +1,36 @@
+version: v0.4.0
+
+listeners:
+  - type: model
+    name: model_listener
+    port: 12000
+
+model_providers:
+  - model: openai/gpt-4o-mini
+    access_key: $OPENAI_API_KEY
+    default: true
+
+  - model: openai/gpt-5.2
+    access_key: $OPENAI_API_KEY
+
+routing_preferences:
+  - name: fast_responses
+    description: short factual questions, quick lookups, simple summarization, or greetings
+    models:
+      - openai/gpt-4o-mini
+
+  - name: deep_reasoning
+    description: multi-step reasoning, complex analysis, code review, or detailed explanations
+    models:
+      - openai/gpt-5.2
+      - openai/gpt-4o-mini
+
+routing:
+  session_ttl_seconds: 300
+  session_cache:
+    type: redis
+    url: redis://localhost:6379
+
+tracing:
+  random_sampling: 100
+  trace_arch_internal: true