Add step 612 canary promotion judge

editor/src/CanaryPromotionJudge.h

@@ -0,0 +1,72 @@
+#pragma once
+// Step 612: Canary Promotion Judge
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "ValidationErrorUtil.h"
+
+struct CanaryAssessment {
+    std::string canaryId;
+    int requestSuccessPercent = 0;
+    int latencyP95Ms = 0;
+    int errorBudgetBurn = 0;
+    bool manualOverride = false;
+};
+
+class CanaryPromotionJudge {
+public:
+    bool record(const CanaryAssessment& assessment, std::string* error) {
+        if (!error) return false;
+        error->clear();
+        if (assessment.canaryId.empty()) return failWith(error, "canary_id_missing");
+        if (assessment.requestSuccessPercent < 0 || assessment.requestSuccessPercent > 100) {
+            return failWith(error, "success_percent_invalid");
+        }
+        if (assessment.latencyP95Ms < 0) return failWith(error, "latency_invalid");
+        if (assessment.errorBudgetBurn < 0) return failWith(error, "error_budget_burn_invalid");
+        if (items_.count(assessment.canaryId) == 0) order_.push_back(assessment.canaryId);
+        items_[assessment.canaryId] = assessment;
+        return true;
+    }
+
+    bool promotable(const std::string& canaryId, std::string* error) const {
+        if (!error) return false;
+        error->clear();
+        auto it = items_.find(canaryId);
+        if (it == items_.end()) return failWith(error, "canary_missing");
+        const auto& a = it->second;
+        if (a.manualOverride) return true;
+        return a.requestSuccessPercent >= 99 && a.latencyP95Ms <= 300 && a.errorBudgetBurn <= 100;
+    }
+
+    int riskScore(const std::string& canaryId, std::string* error) const {
+        if (!error) return 0;
+        error->clear();
+        auto it = items_.find(canaryId);
+        if (it == items_.end()) {
+            failWith(error, "canary_missing");
+            return 100;
+        }
+        const auto& a = it->second;
+        int score = 0;
+        if (a.requestSuccessPercent < 99) score += (99 - a.requestSuccessPercent) * 5;
+        if (a.latencyP95Ms > 300) score += (a.latencyP95Ms - 300) / 5;
+        if (a.errorBudgetBurn > 100) score += (a.errorBudgetBurn - 100) / 2;
+        if (a.manualOverride) score = 0;
+        if (score > 100) return 100;
+        return score;
+    }
+
+    int promotableCount() const {
+        int count = 0;
+        std::string error;
+        for (const auto& id : order_) if (promotable(id, &error)) ++count;
+        return count;
+    }
+
+private:
+    std::map<std::string, CanaryAssessment> items_;
+    std::vector<std::string> order_;
+};