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/debug/DebugMetricsPacket.h

@@ -0,0 +1,52 @@
+#pragma once
+// Step 1467: debugging metrics packet.
+
+#include <string>
+
+#include <nlohmann/json.hpp>
+
+struct DebugMetricsPacket {
+    std::string sessionId;
+    int iterationsToGreen = 0;
+    int timeToGreenMs = 0;
+    int tokenCostPerFix = 0;
+    int symptomToRootCauseCompression = 0;
+    int patchAcceptanceRatePct = 0;
+    int regressionEscapeRatePct = 0;
+};
+
+class DebugMetricsModel {
+public:
+    static DebugMetricsPacket compute(const std::string& sessionId,
+                                      int iterations,
+                                      int durationMs,
+                                      int tokenCost,
+                                      int symptomCount,
+                                      int rootCauseCount,
+                                      int acceptedPatches,
+                                      int proposedPatches,
+                                      int regressions,
+                                      int totalRuns) {
+        DebugMetricsPacket m;
+        m.sessionId = sessionId;
+        m.iterationsToGreen = iterations;
+        m.timeToGreenMs = durationMs;
+        m.tokenCostPerFix = tokenCost;
+        m.symptomToRootCauseCompression = (rootCauseCount == 0) ? 0 : (100 * symptomCount / rootCauseCount);
+        m.patchAcceptanceRatePct = (proposedPatches == 0) ? 0 : (100 * acceptedPatches / proposedPatches);
+        m.regressionEscapeRatePct = (totalRuns == 0) ? 0 : (100 * regressions / totalRuns);
+        return m;
+    }
+
+    static nlohmann::json toJson(const DebugMetricsPacket& m) {
+        return {
+            {"session_id", m.sessionId},
+            {"iterations_to_green", m.iterationsToGreen},
+            {"time_to_green_ms", m.timeToGreenMs},
+            {"token_cost_per_fix", m.tokenCostPerFix},
+            {"symptom_to_root_cause_compression", m.symptomToRootCauseCompression},
+            {"patch_acceptance_rate_pct", m.patchAcceptanceRatePct},
+            {"regression_escape_rate_pct", m.regressionEscapeRatePct}
+        };
+    }
+};