Library: "Continue where you left off" row with a per-user setting

One fixed row above the library showing the five most recently read,
unfinished manga with the normal tiles (they stay in the grid as well).
It ignores search and filters, hides while sorted by "Recently read",
and can be turned off under Settings > Reading > Library page
(continueRow, default on).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test/services.test.js

@@ -67,6 +67,10 @@ test('three services integrate collections, auth, custom covers and private heal
     assert.equal((await (await request('/api/settings', { pageTone: 'sepia' })).json()).settings.pageTone, 'sepia');
     assert.equal((await (await request('/api/settings', { pageTone: 'invalid' })).json()).settings.pageTone, 'sepia');
     assert.equal((await (await anotherRequest('/api/me')).json()).settings.pageTone, 'original');
+    assert.equal((await (await request('/api/me')).json()).settings.continueRow, true);
+    assert.equal((await (await request('/api/settings', { continueRow: false })).json()).settings.continueRow, false);
+    assert.equal((await (await request('/api/settings', { continueRow: 'no' })).json()).settings.continueRow, false);
+    assert.equal((await (await anotherRequest('/api/me')).json()).settings.continueRow, true);
     assert.equal((await fetch(base + '/api/discovery')).status, 401);
     assert.equal((await anotherRequest('/api/admin/discovery/run', {})).status, 403);
     assert.equal((await request('/api/settings', { discoveryEnabled: true })).status, 200);