feat(library): backlog status, rating, notes and priority in the UI

Detail page gets an edit card. The library gets status badges, status filter
chips and a debounced name search, both kept in the URL.

src/utils/backlog.test.js

@@ -0,0 +1,34 @@
+import {describe, expect, it} from 'vitest';
+import {libraryQuery, NO_PRIORITY, parseStatus, toBacklogRequest} from './backlog.js';
+
+describe('toBacklogRequest', () => {
+    it('sends every field', () => {
+        expect(toBacklogRequest({status: 'FINISHED', rating: 4, notes: 'Great', priority: 'HIGH'}))
+            .toEqual({status: 'FINISHED', rating: 4, notes: 'Great', priority: 'HIGH'});
+    });
+
+    it('sends null for cleared fields', () => {
+        expect(toBacklogRequest({status: 'BACKLOG', rating: 0, notes: '   ', priority: NO_PRIORITY}))
+            .toEqual({status: 'BACKLOG', rating: null, notes: null, priority: null});
+    });
+});
+
+describe('parseStatus', () => {
+    it('accepts a known status only', () => {
+        expect(parseStatus('PLAYING')).toBe('PLAYING');
+        expect(parseStatus('playing')).toBeNull();
+        expect(parseStatus(null)).toBeNull();
+    });
+});
+
+describe('libraryQuery', () => {
+    it('leaves out empty filters', () => {
+        expect(libraryQuery({page: 0, size: 20, sort: 'playtimeMinutes,desc', status: null, q: '  '}))
+            .toBe('page=0&size=20&sort=playtimeMinutes%2Cdesc');
+    });
+
+    it('adds status and the trimmed, encoded search', () => {
+        expect(libraryQuery({page: 1, size: 40, sort: 'appid,asc', status: 'DROPPED', q: ' 100% & more '}))
+            .toBe('page=1&size=40&sort=appid%2Casc&status=DROPPED&q=100%25+%26+more');
+    });
+});