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/formats/data_test.cpp

@@ -0,0 +1,26 @@
+// Route: GET /formats/data  (content negotiation)
+#include "support/Assert.hpp"
+
+using namespace molo::example::test;
+using molo::example::fw::Method;
+
+int main() {
+  Fixture f;
+  auto def = f.client->get("/formats/data");
+  check(contains(def.headers.get("Content-Type"), "application/json"),
+        "default is json");
+  auto xml = f.client->request(Method::Get, "/formats/data", "",
+                               {{"Accept", "application/xml"}});
+  check(contains(xml.headers.get("Content-Type"), "application/xml"),
+        "xml negotiated");
+  check(contains(xml.body, "<value>42</value>"), "xml body");
+  auto weighted = f.client->request(
+      Method::Get, "/formats/data", "",
+      {{"Accept", "text/html;q=0.2, text/plain;q=0.9"}});
+  check(contains(weighted.headers.get("Content-Type"), "text/plain"),
+        "q weights honored");
+  auto nope = f.client->request(Method::Get, "/formats/data", "",
+                                {{"Accept", "image/png"}});
+  check(nope.status == 406, "no match is 406");
+  return finish("formats/data");
+}