Step 534: add constrained operation selector API

editor/src/OperationSelectorAPI.h

@@ -0,0 +1,88 @@
+#pragma once
+// Step 534: Operation Selector API
+
+#include <algorithm>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "LegalOperationGraph.h"
+#include "SymbolScopeExtractor.h"
+#include "TypedTaskitemContractSchema.h"
+
+struct OperationCandidate {
+    std::string operation;
+    int score = 0;
+    std::vector<std::string> reasons;
+};
+
+struct OperationSelectionResult {
+    bool supported = false;
+    std::vector<OperationCandidate> candidates;
+};
+
+class OperationSelectorAPI {
+public:
+    static OperationSelectionResult select(
+        const TaskitemContract& contract,
+        const std::string& nodeKind,
+        const ScopeSnapshot& snapshot,
+        const LegalOperationGraph& graph,
+        const std::vector<std::string>& preferredOps = {}) {
+        OperationSelectionResult result;
+        auto legal = graph.allowedOps(contract.language, nodeKind);
+        if (!legal.supported) return result;
+
+        result.supported = true;
+        auto preferred = asSet(preferredOps);
+        for (const auto& op : legal.operations) {
+            if (!TypedTaskitemContractSchema::opAllowed(contract, op)) continue;
+            OperationCandidate c;
+            c.operation = op;
+            c.score = baseScore(op);
+            if (preferred.count(op) > 0) {
+                c.score += 40;
+                c.reasons.push_back("preferred_op");
+            }
+            if (snapshot.supported && !snapshot.candidates.empty()) {
+                c.score += 15;
+                c.reasons.push_back("symbols_in_scope");
+            } else {
+                c.score -= 10;
+                c.reasons.push_back("weak_scope_context");
+            }
+            if (op == "rename" || op == "update") {
+                c.score += 10;
+                c.reasons.push_back("low_constraint_risk");
+            }
+            if (op == "delete") {
+                c.score -= 25;
+                c.reasons.push_back("high_constraint_risk");
+            }
+            result.candidates.push_back(c);
+        }
+
+        std::sort(result.candidates.begin(), result.candidates.end(),
+                  [](const OperationCandidate& a, const OperationCandidate& b) {
+                      if (a.score != b.score) return a.score > b.score;
+                      return a.operation < b.operation;
+                  });
+        return result;
+    }
+
+private:
+    static int baseScore(const std::string& op) {
+        if (op == "rename") return 100;
+        if (op == "update") return 95;
+        if (op == "extract") return 85;
+        if (op == "inline") return 75;
+        if (op == "insert") return 70;
+        if (op == "reorder") return 65;
+        if (op == "delete") return 50;
+        return 40;
+    }
+
+    static std::set<std::string> asSet(const std::vector<std::string>& values) {
+        return std::set<std::string>(values.begin(), values.end());
+    }
+};