docs: add risk model

Author: OgeonX-Ai

docs/risk/README.md

@@ -0,0 +1,27 @@
+# Risk Model
+
+AI-OS separates low-risk documentation work from high-risk automation, release, and security work.
+
+## Risk loop
+
+```mermaid
+flowchart TD
+    A[Proposed change] --> B[Classify risk]
+    B --> C{Risk level}
+    C -- Low --> D[Proceed]
+    C -- Medium --> E[Extra review]
+    C -- High --> F[Maintainer review]
+    D --> G[Verify]
+    E --> G
+    F --> G
+```
+
+## Risk levels
+
+- Low: documentation correction, link update, diagram addition.
+- Medium: workflow change, release note change, governance clarification.
+- High: release process, security policy, repository automation, public publication workflow.
+
+## Output
+
+Every meaningful change should state risk level and verification evidence.