feat: implement MoloApp plans 01-15 with integration

Full C++23 framework tree: runtime, observability, security,
data, app, realtime, supervisor, clients, CLI, example plus
enterprise tenancy, audit, operability, governance,
supplychain. Postgres via docker compose for tests.

tests/example/kv/items_test.cpp

@@ -0,0 +1,19 @@
+// Route: /kv/items
+#include "support/Assert.hpp"
+
+using namespace molo::example::test;
+
+int main() {
+  Fixture f;
+  auto missing = f.client->get("/kv/items?key=nope");
+  check(missing.status == 404, "missing key is 404");
+  auto bad = f.client->post("/kv/items", "{\"key\":\"a\"}",
+                            "application/json");
+  check(bad.status == 400, "key without value is 400");
+  auto put = f.client->post("/kv/items", "{\"key\":\"a\",\"value\":\"b\"}",
+                            "application/json");
+  check(put.status == 201, "store status 201");
+  auto get = f.client->get("/kv/items?key=a");
+  check(contains(get.body, "\"value\":\"b\""), "round trip works");
+  return finish("kv/items");
+}