Watch article history over SSE so the tab stays current while open.

src/api/ApiClient.js

@@ -108,6 +108,12 @@ export class ApiClient {
       get: (sku) => this.#json('GET', `/api/article/${enc(sku)}`),
       /** GET /api/article/{sku}/history → { history: [{ id, date, text }, ...] } */
       history: (sku) => this.#json('GET', `/api/article/${enc(sku)}/history`),
+      /**
+       * Load history and refetch on SSE `article-<sku>`.
+       * `onHistory(history)` / `onError(err)` — returns unwatch().
+       */
+      historyWatch: (sku, onHistory, onError) =>
+        this.watchArticleHistory(sku, onHistory, onError),
       /** PATCH /api/article/{sku} — body: at least one of { name, unitamount, unitSi } */
       update: async (sku, body) => {
         const nameChange = body != null && Object.hasOwn(body, 'name');