fix(i18n): one German word per thing across Settings

Anbieter instead of Provider, Standard instead of Default, Gesundheitsscore
for every spelling of the score, and Insights where the area was called
Auswertungen. The Coach's rate-limit notice no longer shows English in the
German interface. A guard reads the Settings namespaces of the German
catalog and fails on the retired spellings.

src/components/settings/__tests__/ai-section.test.tsx

@@ -218,7 +218,7 @@ describe("<AiSection> — dropdown-driven UX (B2)", () => {
     // both ship without the "KI"/"AI" prefix per the project-voice rule
     // ("Aktiver KI-Provider" → "Aktiver Provider"). The picker below it is
     // labelled for what it does: it chooses the form, not the order.
-    expect(html).toContain("Aktiver Provider");
+    expect(html).toContain("Aktiver Anbieter");
     expect(html).toContain("Anbieter einrichten");
   });