feat: BuildKit client + integration test suite (651 tests)

BuildKitClient CLI wrapper for buildctl.
Docker compose stack (9 services) for integration testing.
Comprehensive test suite: wiremock tests for Matrix/La Suite/S3/client,
integration tests for Kratos/Hydra/Gitea/OpenSearch/Prometheus/Loki/
Grafana/LiveKit.

Bump: sunbeam-sdk v0.12.0

sunbeam-sdk/tests/config/identity.schema.json

@@ -0,0 +1,27 @@
+{
+  "$id": "https://schemas.sunbeam.pt/default.schema.json",
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "Default identity",
+  "type": "object",
+  "properties": {
+    "traits": {
+      "type": "object",
+      "properties": {
+        "email": {
+          "type": "string",
+          "format": "email",
+          "title": "Email",
+          "ory.sh/kratos": {
+            "credentials": {
+              "password": { "identifier": true }
+            },
+            "recovery": { "via": "email" },
+            "verification": { "via": "email" }
+          }
+        }
+      },
+      "required": ["email"],
+      "additionalProperties": true
+    }
+  }
+}