feat(reputation): translate rank labels to English

Translates the six REPUTATION_RANKS labels in reputation-rank.ts
(Geachtet/Vertraut/Anerkannt/Bekannt/Geduldet/Fremder -> Esteemed/
Trusted/Recognized/Known/Tolerated/Stranger), per the glossary in
docs/superpowers/specs/2026-08-21-english-game-content-foundation-design.md
section 4. Keys and thresholds are unchanged.

Also updates reputation.service.spec.ts and reputation.controller.spec.ts,
which asserted the German rankLabel value returned by
resolveReputationRank() via the service/controller layer.

apps/api/src/reputation/reputation-rank.spec.ts

@@ -4,7 +4,7 @@ describe('resolveReputationRank', () => {
   it('resolves 0 reputation to Stranger with a next threshold of 100', () => {
     expect(resolveReputationRank(0)).toEqual({
       key: 'STRANGER',
-      label: 'Fremder',
+      label: 'Stranger',
       threshold: 0,
       nextThreshold: 100,
     });