feat(library): Filters shows its active count; final review follow-ups

- D44: the shared toolbar's Filters button reads "Filters · N" while N
  "Refine this view" filters are active (Library: Tags; Images: Source,
  Folder, Media, Tags), so a Browse-set Tags filter is visible on the
  shelf. The text is the accessible name. Unit and browser tests cover
  Browse -> "Filters · 1" -> Clear -> "Filters" and the Images counts.
- Renumber the alphabetical tag chips deviation D42 -> D43 (D42 is #264's).
- The caption count is a role=status region written only when it changes
  and kept shown while the shelf reloads.
- usedLabel names the year for a use in another calendar year (D23).
- prompt-blocks: same `title` option API as #264 (`subject` suffix); the
  region-name helper's parameter no longer shadows it.
- Scope library.css .row-actions rules to the history panels; fix stale
  CSS and spec comments.
- Retry re-reading a failed category list and the no-op Apply/search
  paths are covered by a browser test.
- TESTING.md: D23 amendments (year, button vs link trade-off), D44, the
  legacy Library link wording.

tests/js/workspace-images-state.test.js

@@ -248,6 +248,15 @@ test('the scope chip summarizes source and folder', async () => {
     assert.equal(scopeLabel({root:'7',subfolder:''},roots),'Source 7 · All output folders');
 });
 
+test('the Filters count names each active Refine filter once (D44)', async () => {
+    const {activeRefinements}=await source;
+    assert.equal(activeRefinements({root:'all',subfolder:'',media:'all',tags:[]}),0);
+    assert.equal(activeRefinements({root:'',subfolder:'',media:'all',tags:[]}),0);
+    assert.equal(activeRefinements({root:'1',subfolder:'',media:'all',tags:[]}),1);
+    assert.equal(activeRefinements({root:'all',subfolder:'bulk',media:'video',tags:['a','b']}),3);
+    assert.equal(activeRefinements({root:'0',subfolder:'bulk',media:'image',tags:['a']}),4);
+});
+
 test('the card title is the confirmed linked title, else the filename (D10)', async () => {
     const {cardTitle}=await source;
     const linked=(status,title)=>({filename:'alpine_00001.png',linked:{status,positive_id:1,title,title_source:'title',category:null,rating:null}});

tests/js/workspace-library-format.test.js

@@ -23,6 +23,9 @@ test('used label boundaries in UTC and local time', async () => {
         assert.equal(usedLabel('2026-10-14T00:00:00Z', now), 'Used 6 days ago');
         assert.equal(usedLabel('2026-10-13T23:59:59Z', now), 'Used Oct 13');
         assert.equal(usedLabel('2026-01-02T08:00:00Z', now), 'Used Jan 2');
+        // D23: a use in another calendar year names its year, so last year's Oct 21 never reads as this year's.
+        assert.equal(usedLabel('2025-10-21T08:00:00Z', now), 'Used Oct 21, 2025');
+        assert.equal(usedLabel('2025-12-31T23:59:59Z', now), 'Used Dec 31, 2025');
         // A clock ahead of this browser is not a future use: it reads as today.
         assert.equal(usedLabel('2026-10-21T09:00:00Z', now), 'Used today');
     });

tests/js/workspace-toolbar.test.js

@@ -611,3 +611,30 @@ test('every route change closes the shared workspace dialog', async () => {
     const body = render.slice(0, render.indexOf('viewScope = createScope();'));
     assert.match(body, /closeWorkspaceDialog\(\);/, 'render closes the dialog before the next page mounts');
 });
+
+// D44: the concept has no indicator, so a filter set in "Refine this view" (or by Browse) was invisible on the page.
+test('the Filters button shows the active refinement count', async () => {
+    const { mountToolbar } = await toolbarModule;
+    const { createScope } = await import('../../web/js/shared/toolkit/core.js');
+    const dom = fakeDOM();
+    const scope = createScope();
+    try {
+        const container = new dom.Element('div');
+        const toolbar = mountToolbar(container, { scope, categories: [], sorts: [['newest', 'Recently added']],
+            activeFilters: 2, onChange() {}, onFilters() {} });
+        const filtersButton = container.children[0].children[3];
+        // The visible text is the accessible name, so the count is spoken too.
+        assert.equal(filtersButton.textContent, 'Filters · 2');
+        toolbar.setActiveFilters(1);
+        assert.equal(filtersButton.textContent, 'Filters · 1');
+        toolbar.setActiveFilters(0);
+        assert.equal(filtersButton.textContent, 'Filters');
+        for (const bad of [-1, 1.5, '1', null, Number.NaN]) assert.throws(() => toolbar.setActiveFilters(bad), TypeError);
+        assert.equal(filtersButton.textContent, 'Filters');
+        assert.throws(() => mountToolbar(new dom.Element('div'), { scope, categories: [], sorts: [['newest', 'Recently added']],
+            activeFilters: -1, onChange() {}, onFilters() {} }), TypeError);
+    } finally {
+        scope.dispose();
+        dom.restore();
+    }
+});