Standardize UI typography, charts and empty states

tests/unit/ui-capacity.test.ts

@@ -39,6 +39,8 @@ it('keeps current estimates and host comparison before history with scoped histo
     expect(body).toContain('No queued instances');
     expect(body).not.toContain('href="/provisioning"');
     expect(body).not.toContain('Manage hosts');
+    expect(body).toContain('Updates every 30 seconds');
+    expect(body).not.toContain('>Refresh<');
 });
 
 it('keeps fleet-wide queue scope explicit and preserves unavailable estimates', () => {
@@ -61,6 +63,7 @@ it('keeps ineligible hosts and their reasons visible while collapsing detailed a
     expect(body).toMatch(/<tr hidden[^>]*id="capacity-host-ec-1"/);
     expect(body).toContain('aria-expanded="false"');
     expect(body).toContain('Running instance');
+    expect(body).toContain('aria-label="Host capacity comparison" tabindex="0"');
 });
 
 it('preserves chart gaps, keyboard inspection and reporting coverage in the compact chart', () => {