Checkpoint the party/runtime stack before share-program and malicious-mode work.

Ship the TLS mesh, composer, Beaver/Yao/leaf MPC, prep/online paths, apps, and docs so the tree is pushable before elevating share_expr, security_mode, and prep resume.

Co-authored-by: Cursor <cursoragent@cursor.com>

examples/applications/keyword_pir.cpp

@@ -0,0 +1,60 @@
+#include <cstdint>
+#include <iostream>
+#include <string>
+#include <vector>
+
+#include "dpf.hpp"
+#include "dpf/app_flow.hpp"
+#include "dpf/app_plans.hpp"
+
+// Two-server keyword PIR, the DPF step (Gilboa and Ishai, EUROCRYPT 2014).
+// `eval_sequence_xor` folds the selected records into one XOR accumulator
+// without materializing a bit vector.
+//
+//   c++ -std=c++17 -march=native -pthread -I include -I thirdparty \
+//       examples/applications/keyword_pir.cpp
+//   DPF_EXPERIMENT_DIR=/tmp/kw ./a.out   # optional CSV dump
+
+namespace
+{
+
+using keyword = dpf::keyword<3, dpf::alphabets::lowercase_alpha>;
+
+}  // namespace
+
+int main()
+{
+    const std::vector<keyword> dict{keyword{"bat"}, keyword{"cat"},
+        keyword{"dog"}, keyword{"pig"}};
+    const std::vector<int> records{56, 12, 34, 78};
+
+    auto [k0, k1] = dpf::make_dpf(keyword{"bat"}, dpf::bit::one);
+    const int selected = dpf::eval_sequence_xor(k0, dict.begin(), dict.end(),
+                            records)
+        ^ dpf::eval_sequence_xor(k1, dict.begin(), dict.end(), records);
+    if (selected != 56)
+    {
+        std::cerr << "keyword hit\n";
+        return 1;
+    }
+
+    auto [m0, m1] = dpf::make_dpf(keyword{"rat"}, dpf::bit::one);
+    const int missing = dpf::eval_sequence_xor(m0, dict.begin(), dict.end(),
+                            records)
+        ^ dpf::eval_sequence_xor(m1, dict.begin(), dict.end(), records);
+    if (missing != 0)
+    {
+        std::cerr << "keyword miss\n";
+        return 1;
+    }
+
+    {
+        constexpr std::size_t depth = dpf::utils::bitlength_of<keyword>::value;
+        if (int rc = dpf::app::run_measured("keyword_pir",
+                dpf::protocol::keyword_pir_compose_plan(0, depth), 2))
+            return rc;
+    }
+
+    std::cout << selected << "\n";
+    return 0;
+}