tests: pin the adapter lookup-index populations with a read-only probe

src/source/pine_adapter.cpp

@@ -30298,6 +30298,8 @@ std::array<std::uint64_t, 3> PineExecutionAdapter::retirement_validation_state()
 #endif
 } // namespace pineforge::source
 
+#include "pine_adapter_probe.hpp"
+
 namespace pineforge::source::detail {
 
 CohortExposureFold fold_cohort_exposure(
@@ -30452,4 +30454,21 @@ void verify_cohort_exposure(
 }
 #endif
 
+LookupIndexCounts probe_lookup_index(const NativeHostCache* cache) noexcept {
+    if (cache == nullptr || typeid(*cache) != typeid(AdapterLookupIndex)) return {};
+    const auto& index = static_cast<const AdapterLookupIndex&>(*cache);
+    LookupIndexCounts counts{true, index.cohort_sides.size(), index.unbound.size()};
+    std::size_t kind = 0;
+    for (const auto& by_origin : index.legs_by_origin) {
+        counts.legs_by_origin_keys[kind] = by_origin.size();
+        for (const auto& row : by_origin)
+            counts.legs_by_origin_ids[kind] += row.second.size();
+        ++kind;
+    }
+    counts.immediate_closes_keys = index.immediate_closes_by_bar.size();
+    for (const auto& row : index.immediate_closes_by_bar)
+        counts.immediate_closes_ids += row.second.size();
+    return counts;
+}
+
 } // namespace pineforge::source::detail

src/source/pine_adapter_probe.hpp

@@ -0,0 +1,25 @@
+#pragma once
+
+#include "pine_host_reads.hpp"
+
+#include <array>
+#include <cstddef>
+
+namespace pineforge::source::detail {
+
+// Pure reader: no unordered-map operator[], only size() and iteration over
+// values into std::array counters. No allocation, no mutation, nothing hashed.
+// The three slots are ExitLimit, ExitStop and ExitTrail, in that order.
+struct LookupIndexCounts {
+    bool present = false;
+    std::size_t cohort_sides = 0;
+    std::size_t unbound = 0;
+    std::array<std::size_t, 3> legs_by_origin_keys{};
+    std::array<std::size_t, 3> legs_by_origin_ids{};
+    std::size_t immediate_closes_keys = 0;
+    std::size_t immediate_closes_ids = 0;
+};
+
+LookupIndexCounts probe_lookup_index(const NativeHostCache* cache) noexcept;
+
+} // namespace pineforge::source::detail

tests/cr150.d/adapter-lookup-index-counts.cmake

@@ -0,0 +1,4 @@
+if(PINEFORGE_BUILD_SOURCE_LAYER)
+    list(APPEND TEST_SOURCES test_adapter_lookup_index_counts)
+    pineforge_add_unit_test(test_adapter_lookup_index_counts)
+endif()