Add centralized pipeline fallback notifier

test/pipeline-fallback-notifier.test.mjs

@@ -0,0 +1,28 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+const {PipelineFallbackNotificationRegistry} = await import("../dist/ai/user-request-pipeline/fallback-notifier-registry.js");
+const {resolvePipelineFallbackText} = await import("../dist/ai/user-request-pipeline/fallback-notifier-text.js");
+
+test("pipeline fallback text maps notify_user to a user-facing message", () => {
+    assert.match(resolvePipelineFallbackText("document_rag", "notify_user"), /RAG/i);
+    assert.match(resolvePipelineFallbackText("speech_to_text", "notify_user"), /transcription/i);
+    assert.match(resolvePipelineFallbackText("tool_loop", "notify_user"), /tool/i);
+});
+
+test("pipeline fallback text stays silent for continue_without_stage", () => {
+    assert.equal(resolvePipelineFallbackText("document_rag", "continue_without_stage"), undefined);
+    assert.equal(resolvePipelineFallbackText("tool_loop", "continue_without_stage"), undefined);
+});
+
+test("pipeline fallback notification registry deduplicates one request-stage-action", () => {
+    const registry = new PipelineFallbackNotificationRegistry();
+    const decision = {
+        stage: "tool_loop",
+        action: "notify_user",
+    };
+
+    assert.equal(registry.claim("request-1", decision), true);
+    assert.equal(registry.claim("request-1", decision), false);
+    assert.equal(registry.claim("request-2", decision), true);
+});