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/metrics/counters_test.cpp

@@ -0,0 +1,15 @@
+// Route: GET /metrics/counters  (prometheus render)
+#include "support/Assert.hpp"
+
+using namespace molo::example::test;
+
+int main() {
+  Fixture f;
+  auto first = f.client->get("/metrics/counters");
+  check(first.status == 200, "status 200");
+  check(contains(first.body, "example.page.views 1"), "counter at 1");
+  f.client->get("/metrics/counters");
+  check(f.services.metrics->get("example.page.views") == 2.0,
+        "side effect: counter at 2");
+  return finish("metrics/counters");
+}