add generation cancellation middleware and refactor chat/message workflows to support HTTP client disconnections

test/conversation.test.js

@@ -0,0 +1,22 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+test("conversation navigation", async t => {
+    const original = Object.fromEntries(["document", "window", "history", "location"].map(key => [key, globalThis[key]]));
+    const elements = new Map();
+    globalThis.document = {
+        getElementById(id) {
+            if (!elements.has(id)) elements.set(id, {value: "", textContent: "", querySelectorAll: () => []});
+            return elements.get(id);
+        },
+        querySelectorAll: () => [], querySelector: () => null
+    };
+    globalThis.location = {pathname: "/app/chats/1", search: ""};
+    globalThis.window = {location: globalThis.location};
+    globalThis.history = {replaceState(_data, _unused, path) { globalThis.location.pathname = path; }};
+    t.after(() => { for (const [key, value] of Object.entries(original)) globalThis[key] = value; });
+    const {registerConversationTests} = await import("../browser-tests/conversationCases.js");
+    const cases = [];
+    registerConversationTests((name, run) => cases.push({name, run}), assert);
+    for (const {name, run} of cases) await t.test(name, run);
+});