feat: establish read-only DocForge MCP foundation

schemas/changeset.schema.json

@@ -0,0 +1,36 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://docforge.local/schema/changeset-v1.json",
+  "title": "DocForge isolated changeset",
+  "type": "object",
+  "required": ["schema_version", "changeset_id", "project_id", "root_fingerprint", "base_revision", "base_source_hash", "creator", "operations"],
+  "properties": {
+    "schema_version": { "const": 1 },
+    "changeset_id": { "type": "string", "pattern": "^[a-z0-9][a-z0-9._-]{1,127}$" },
+    "project_id": { "type": "string" },
+    "root_fingerprint": { "type": "string" },
+    "base_revision": { "type": "string" },
+    "base_source_hash": { "type": "string", "pattern": "^[0-9a-f]{64}$" },
+    "creator": { "type": "string", "minLength": 1 },
+    "operations": {
+      "type": "array",
+      "minItems": 1,
+      "items": {
+        "type": "object",
+        "required": ["operation", "node_id", "expected_content_hash", "rationale"],
+        "properties": {
+          "operation": { "enum": ["create", "update", "move", "delete"] },
+          "node_id": { "type": "string", "pattern": "^[a-z0-9][a-z0-9._-]{1,127}$" },
+          "expected_content_hash": { "type": ["string", "null"] },
+          "target_source": { "type": ["string", "null"] },
+          "metadata": { "type": ["object", "null"] },
+          "content": { "type": ["string", "null"] },
+          "relationship_changes": { "type": "array" },
+          "rationale": { "type": "string", "minLength": 1 }
+        },
+        "additionalProperties": false
+      }
+    }
+  },
+  "additionalProperties": false
+}