fix: align pending questions by native occurrence

tests/pending-authority.test.ts

@@ -1,16 +1,20 @@
 import assert from "node:assert/strict";
 import { test } from "node:test";
 import { findPendingToolCall } from "../src/core/pending.ts";
-import { danglingQuestionOf, newAnswerResult, type LhMessage } from "../src/core/native-messages.ts";
+import { danglingQuestionOf, pendingQuestionOf, newAnswerResult, newUserMessage, type LhMessage } from "../src/core/native-messages.ts";
 import { inputAppends } from "../src/core/input-events.ts";
 import { projectView } from "../src/core/view.ts";
 
 function assistant(id: string, ...calls: string[]): LhMessage {
-	return { id, role: "assistant", content: calls.map(id => ({ type: "toolCall", id, name: "quiz", arguments: { question: id } })), stopReason: "toolUse", timestamp: 1 } as LhMessage;
+	return {
+		id, role: "assistant", content: calls.map(id => ({ type: "toolCall", id, name: "quiz", arguments: { question: id } })),
+		stopReason: "toolUse", timestamp: 1, api: "openai-completions", provider: "fixture", model: "fixture",
+		usage: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, totalTokens: 0, cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 } },
+	};
 }
 
 function pending(messages: LhMessage[], view = projectView(messages)) {
-	return findPendingToolCall(view, danglingQuestionOf(messages)?.toolCallId ?? null);
+	return findPendingToolCall(view, pendingQuestionOf(messages));
 }
 
 test("a later assistant question supersedes an unanswered question in the same projected group", () => {
@@ -38,3 +42,66 @@ test("the authoritative question still waits for projected input validation", ()
 	}
 	assert.equal(pending(messages, view), null);
 });
+
+// Synthetic compatibility cases, not claims about the affected user's history.
+test("reused ids select the newest native question's input, not an older available part", () => {
+	const old = assistant("old", "call_0");
+	const newer = assistant("new", "call_0");
+	if (newer.role === "assistant") newer.content.unshift({ type: "text", text: "new teaching" });
+	if (newer.role === "assistant" && newer.content[1]?.type === "toolCall") newer.content[1].arguments = { question: "NEW" };
+	const messages = [old, newer];
+	const question = pending(messages)!;
+	assert.equal(question.messageId, "new");
+	assert.equal(question.contentIndex, 1);
+	assert.deepEqual(question.input, { question: "NEW" });
+	assert.notEqual(question.key, pending([old])!.key);
+	assert.deepEqual(danglingQuestionOf(messages), { toolCallId: "call_0", tool: "quiz", input: { question: "NEW" } }, "server authority/shape unchanged");
+	const answered = inputAppends({ messages }, { type: "answer", toolCallId: question.toolCallId, answer: { kind: "quiz", answers: [] } as never });
+	const parts = projectView([...messages, ...answered]).flatMap(m => m.parts).filter(p => p.type === "tool-quiz");
+	assert.equal(parts[0]!.state, "input-available", "old transcript card is untouched");
+	assert.equal(parts[1]!.state, "output-available", "result still pairs newest-first");
+	assert.equal(pending([...messages, ...answered]), null);
+});
+
+for (const state of ["input-streaming", "output-error", "output-available"]) {
+	test(`an older available duplicate never bypasses the authoritative part's ${state} state`, () => {
+		const messages = [assistant("old", "call_0"), assistant("new", "call_0")];
+		const view = projectView(messages);
+		const ownPart = view.flatMap(m => m.parts).find(p => p.sourceMessageId === "new" && p.type === "tool-quiz")!;
+		ownPart.state = state;
+		assert.equal(pending(messages, view), null);
+	});
+}
+
+test("a missing authoritative part cannot fall back to another occurrence", () => {
+	const messages = [assistant("old", "call_0"), assistant("new", "call_0")];
+	assert.equal(pending(messages, projectView(messages.slice(0, 1))), null);
+});
+
+test("older questions never revive across display groups or after a text-only newest assistant", () => {
+	const messages = [assistant("old", "old-q"), newUserMessage("another turn"), assistant("new", "new-q")];
+	assert.equal(pending(messages)?.toolCallId, "new-q");
+	assert.equal(pending([...messages, newAnswerResult("new-q", "quiz", {} as never)]), null);
+	const textOnly = { ...assistant("text"), content: [{ type: "text", text: "done" }] } as LhMessage;
+	assert.equal(pending([...messages, textOnly]), null);
+});
+
+test("unique question keys survive live-to-persisted message stamps without resetting drafts", () => {
+	const live = assistant("c_live", "unique-q");
+	const persisted = { ...live, id: "persisted" };
+	assert.equal(pending([live])!.key, pending([persisted])!.key);
+	assert.notEqual(pending([live])!.messageId, pending([persisted])!.messageId);
+});
+
+test("native occurrence checks preserve every question tool and its own live validation gate", () => {
+	for (const tool of ["quiz", "probe", "ask_user_question", "explain", "recall"]) {
+		const message = assistant("live", "q");
+		if (message.role === "assistant" && message.content[0]?.type === "toolCall") message.content[0].name = tool;
+		const live = { executions: new Map(), inFlight: true, streamingIds: new Set(["live"]) };
+		assert.equal(pending([message], projectView([message], live)), null);
+		live.executions.set("q", { isError: false });
+		assert.equal(pending([message], projectView([message], live))?.tool, tool);
+		live.executions.set("q", { isError: true });
+		assert.equal(pending([message], projectView([message], live)), null);
+	}
+});