init: seed framework reference content from agent-runtimes main repo

harnesses/contexts/airouter/v1/harness.yaml

@@ -0,0 +1,14 @@
+kind: context
+name: airouter
+version: 1
+description: "Airouter.ch Qwen3.6 — OpenAI-compatible agentic runner"
+requires: []
+provides: [agentic-runner]
+
+env:
+  OPENAI_BASE_URL: "https://api.airouter.ch/v1"
+
+secrets_files:
+  - source: ./provider.sops.env
+    target: /opt/harness/secrets/airouter/provider.sops.env
+    encrypted: true