feat(library): set status and rating in one step (#56)

Library rows: the status badge is a menu that saves at once.
Game page: status and rating in the top card, saved on click.
Status changes and hiding a game show an Undo toast.
Other game actions moved into a "..." menu; split and unlink ask first.
New sorts: name, last played, time to beat; "last synced" is gone.
Page numbers and 44 px touch targets on phones.

src/hooks/useSaveBacklogField.js

@@ -0,0 +1,45 @@
+import {useRef, useState} from 'react';
+import {useTranslation} from 'react-i18next';
+import {toast} from 'sonner';
+import {saveBacklogEntry, toBacklogRequest} from '../utils/backlog.js';
+
+/**
+ * Returns `{save, pending, busy}`. `save(field, value)` sends that one field (PATCH .../backlog; 0 or NONE clear it),
+ * shows the saved or error toast and calls `onSaved(entry)` with the whole saved entry. One request at a time: a call
+ * while one runs does nothing. Resolves to true when saved.
+ *
+ * `pending` is `{field, value}` while saving, else null. Show `pending.value` for that field meanwhile: a failed save
+ * then falls back to the saved value by itself.
+ */
+export default function useSaveBacklogField(appid, {onSaved} = {}) {
+    const {t} = useTranslation();
+    const [pending, setPending] = useState(null);
+    const running = useRef(false);
+
+    const save = async (field, value) => {
+        if (running.current) return false;
+        running.current = true;
+        setPending({field, value});
+        try {
+            const response = await saveBacklogEntry(appid, {[field]: toBacklogRequest({[field]: value})[field]});
+            if (response.status === 401) return false;
+            if (!response.ok) {
+                toast.error(t('BACKLOG.SAVE_FAILED'));
+                return false;
+            }
+            const entry = await response.json();
+            onSaved?.(entry);
+            toast.success(t('BACKLOG.SAVED'));
+            return true;
+        } catch (err) {
+            console.error('backlog save error:', err);
+            toast.error(t('INFO.ERROR.NETWORK_FAILURE'));
+            return false;
+        } finally {
+            running.current = false;
+            setPending(null);
+        }
+    };
+
+    return {save, pending, busy: pending !== null};
+}