feat(webui): add initial webui with websocket chat flow

webui/src/tests/api.test.ts

@@ -0,0 +1,37 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+import { deleteSession, fetchSessionMessages } from "@/lib/api";
+
+describe("webui API helpers", () => {
+  beforeEach(() => {
+    vi.stubGlobal(
+      "fetch",
+      vi.fn().mockResolvedValue({
+        ok: true,
+        json: async () => ({ deleted: true, key: "websocket:chat-1", messages: [] }),
+      }),
+    );
+  });
+
+  it("percent-encodes websocket keys when fetching session history", async () => {
+    await fetchSessionMessages("tok", "websocket:chat-1");
+
+    expect(fetch).toHaveBeenCalledWith(
+      "/api/sessions/websocket%3Achat-1/messages",
+      expect.objectContaining({
+        headers: { Authorization: "Bearer tok" },
+      }),
+    );
+  });
+
+  it("percent-encodes websocket keys when deleting a session", async () => {
+    await deleteSession("tok", "websocket:chat-1");
+
+    expect(fetch).toHaveBeenCalledWith(
+      "/api/sessions/websocket%3Achat-1/delete",
+      expect.objectContaining({
+        headers: { Authorization: "Bearer tok" },
+      }),
+    );
+  });
+});