Add context packs impact analysis and message validation

specs/versions/0.1/gsp.message.schema.json

@@ -0,0 +1,63 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://gsp.local/schema/gsp.message.schema.json",
+  "title": "GSP Message",
+  "description": "GSP agent communication message schema.",
+  "type": "object",
+  "additionalProperties": true,
+  "required": ["gspMessageVersion", "id", "from", "to", "intent", "entry"],
+  "properties": {
+    "gspMessageVersion": {
+      "type": "string",
+      "enum": ["0.1"]
+    },
+    "id": {
+      "type": "string",
+      "minLength": 1
+    },
+    "from": {
+      "type": "string",
+      "minLength": 1
+    },
+    "to": {
+      "type": "string",
+      "minLength": 1
+    },
+    "intent": {
+      "type": "string",
+      "enum": ["design", "implement", "review", "test", "acceptance", "handoff", "inspect"]
+    },
+    "entry": {
+      "type": "string",
+      "minLength": 1
+    },
+    "stage": {
+      "type": "string",
+      "enum": ["design", "integrate", "implement", "bind", "release"]
+    },
+    "requires": {
+      "type": "array",
+      "items": {
+        "type": "string",
+        "minLength": 1
+      }
+    },
+    "contextPack": {
+      "type": "object",
+      "additionalProperties": true,
+      "properties": {
+        "mode": {
+          "type": "string",
+          "enum": ["design", "implement", "review", "test", "acceptance", "handoff", "inspect"]
+        },
+        "depth": {
+          "type": "integer"
+        },
+        "budget": {
+          "type": "integer",
+          "minimum": 0
+        }
+      }
+    }
+  }
+}