Add Sprints 46-59: governance, porting foundation, and language graduation prep (Steps 689-828)

Sprints 46-58 implement the cross-language porting foundation: language-to-IR
adapters, equivalence checking, gate validation, legacy ingestion, managed/dynamic
families, low-level/logic-actor semantics, debug workflow tooling, AST-native
family tools, Rust/CPP raising tools, system-level orchestration, query family,
and porting gates. Sprint 59 adds the governance layer (policy packs, review
boards, waiver packets, ambiguity triage, decision ledger) with the
whetstone_review_porting_decision MCP tool.

Also includes: sprint plans 46-130, MCP taskitem pipeline scripts,
CLAUDE.md, docs, and full test matrix (steps 689-828).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

editor/src/cpp_ir/CppOwnershipMappingPolicy.h

@@ -0,0 +1,59 @@
+#pragma once
+// Step 709: ownership mapping policy engine.
+
+#include <algorithm>
+#include <map>
+#include <string>
+#include <vector>
+
+#include <nlohmann/json.hpp>
+
+#include "SemanticCoreIR.h"
+
+struct CppOwnershipDecision {
+    std::string nodeId;
+    std::string strategy; // unique_ptr, shared_ptr, value
+    std::string reason;
+};
+
+class CppOwnershipMappingPolicy {
+public:
+    static std::vector<CppOwnershipDecision> map(const SemanticCoreIR& ir,
+                                                 const std::string& profile = "safe-first") {
+        std::vector<CppOwnershipDecision> out;
+        for (const auto& n : ir.nodes) {
+            if (n.kind != IRNodeKind::OwnershipRegion && n.kind != IRNodeKind::Type) continue;
+            CppOwnershipDecision d;
+            d.nodeId = n.id;
+            if (hasTag(n, "shared")) {
+                d.strategy = "shared_ptr";
+                d.reason = "shared_access_detected";
+            } else if (hasTag(n, "stateful") || profile == "safe-first") {
+                d.strategy = "unique_ptr";
+                d.reason = "exclusive_owner_default";
+            } else {
+                d.strategy = "value";
+                d.reason = "perf_value_default";
+            }
+            if (profile == "interop-first" && d.strategy == "unique_ptr") {
+                d.strategy = "value";
+                d.reason = "interop_abi_friendly";
+            }
+            out.push_back(std::move(d));
+        }
+        std::sort(out.begin(), out.end(), [](const auto& a, const auto& b) { return a.nodeId < b.nodeId; });
+        return out;
+    }
+
+    static nlohmann::json toJson(const std::vector<CppOwnershipDecision>& d) {
+        nlohmann::json j = nlohmann::json::array();
+        for (const auto& x : d) j.push_back({{"nodeId", x.nodeId}, {"strategy", x.strategy}, {"reason", x.reason}});
+        return j;
+    }
+
+private:
+    static bool hasTag(const IRNode& n, const std::string& tag) {
+        for (const auto& t : n.intentTags) if (t == tag) return true;
+        return false;
+    }
+};