feat: add artifact schema registry

docs/schemas/artifacts/dev/spec@1.json

@@ -0,0 +1,38 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "dev/spec@1",
+  "title": "Devflow Development Specification",
+  "type": "object",
+  "additionalProperties": false,
+  "required": ["summary", "requirements", "acceptanceCriteria", "risks"],
+  "properties": {
+    "summary": { "type": "string", "minLength": 1 },
+    "requirements": {
+      "type": "array",
+      "minItems": 1,
+      "items": {
+        "type": "object",
+        "additionalProperties": false,
+        "required": ["id", "description"],
+        "properties": {
+          "id": { "type": "string", "pattern": "^[A-Za-z][A-Za-z0-9_-]*$" },
+          "description": { "type": "string", "minLength": 1 },
+          "priority": { "type": "string", "enum": ["low", "medium", "high"] }
+        }
+      }
+    },
+    "acceptanceCriteria": {
+      "type": "array",
+      "minItems": 1,
+      "items": { "type": "string", "minLength": 1 }
+    },
+    "risks": {
+      "type": "array",
+      "items": { "type": "string", "minLength": 1 }
+    },
+    "openQuestions": {
+      "type": "array",
+      "items": { "type": "string", "minLength": 1 }
+    }
+  }
+}