feat(webui): add model settings runtime refresh

webui/src/lib/api.ts

@@ -1,4 +1,4 @@
-import type { ChatSummary } from "./types";
+import type { ChatSummary, SettingsPayload, SettingsUpdate } from "./types";
 
 export class ApiError extends Error {
   status: number;
@@ -104,3 +104,21 @@ export async function deleteSession(
   );
   return body.deleted;
 }
+
+export async function fetchSettings(
+  token: string,
+  base: string = "",
+): Promise<SettingsPayload> {
+  return request<SettingsPayload>(`${base}/api/settings`, token);
+}
+
+export async function updateSettings(
+  token: string,
+  update: SettingsUpdate,
+  base: string = "",
+): Promise<SettingsPayload> {
+  const query = new URLSearchParams();
+  if (update.model !== undefined) query.set("model", update.model);
+  if (update.provider !== undefined) query.set("provider", update.provider);
+  return request<SettingsPayload>(`${base}/api/settings/update?${query}`, token);
+}