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/templates/page_test.cpp

@@ -0,0 +1,18 @@
+// Route: GET /templates/page  (extends, blocks, for, filters, escape)
+#include "support/Assert.hpp"
+
+using namespace molo::example::test;
+
+int main() {
+  Fixture f;
+  auto res = f.client->get("/templates/page");
+  check(res.status == 200, "status 200");
+  check(contains(res.body, "<title>Templates</title>"),
+        "base layout applied");
+  check(contains(res.body, "Author: ADA"), "upper filter ran");
+  check(contains(res.body, "&lt;b&gt;bold&lt;/b&gt;"),
+        "default output escaped");
+  check(contains(res.body, "<b>bold</b>"), "safe opt-out kept markup");
+  check(contains(res.body, "extends (inheritance)"), "for loop rendered");
+  return finish("templates/page");
+}