feat: add knowledge-driven joint design studio

backend/knowledge/schemas/relation.schema.json

@@ -0,0 +1,19 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "kb://schemas/relation.schema.json",
+  "title": "Mechanical relation knowledge entry",
+  "type": "object",
+  "required": ["schema_version", "id", "version", "relation_type", "endpoint_rules", "constraint_rules", "capability_refs", "maturity"],
+  "properties": {
+    "schema_version": {"const": "1.0"},
+    "id": {"type": "string", "pattern": "^relation\\."},
+    "version": {"type": "string"},
+    "relation_type": {"type": "string"},
+    "endpoint_rules": {"type": "object"},
+    "constraint_rules": {"type": "array", "items": {"type": "string"}},
+    "kinematic_effect": {"type": ["object", "null"]},
+    "capability_refs": {"type": "array", "items": {"type": "string"}, "uniqueItems": true},
+    "maturity": {"type": "string"}
+  },
+  "additionalProperties": false
+}