Route tool ranker fallback through executor

test/tool-ranker-fallback.test.mjs

@@ -2,7 +2,10 @@ import test from "node:test";
 import assert from "node:assert/strict";
 
 const {ToolRankerFallbackPolicy} = await import("../dist/common/policies.js");
-const {resolveToolRankerFallbackSelection} = await import("../dist/ai/tool-ranker-fallback.js");
+const {
+    decideToolRankerFallback,
+    resolveToolRankerFallbackSelection,
+} = await import("../dist/ai/tool-ranker-fallback.js");
 
 const availableToolNames = ["read_file", "search_files"];
 
@@ -32,6 +35,26 @@ test("tool ranker fallback returns all tools when policy is ALL_TOOLS", () => {
     );
 });
 
+test("tool ranker fallback decision uses executor semantics", () => {
+    assert.deepEqual(
+        decideToolRankerFallback({
+            fallbackPolicy: ToolRankerFallbackPolicy.MAIN_MODEL,
+            availableToolNames,
+            reason: "failed",
+        }),
+        {
+            stage: "tool_rank",
+            reason: "failed",
+            action: "use_alternate_target",
+            shouldContinue: true,
+            shouldNotifyUser: false,
+            shouldFailRequest: false,
+            toolNames: ["read_file", "search_files"],
+            usedRanker: false,
+        },
+    );
+});
+
 test("tool ranker fallback keeps all tools when policy is MAIN_MODEL", () => {
     assert.deepEqual(
         resolveToolRankerFallbackSelection({