fix: correct final whole-branch review findings for 0.6.6 English content

- TRAVELLING spelling: fix TRAVELING -> TRAVELLING in travel-panel.component.html
  to match UK spelling used everywhere else (world/hunting/combat stores + API
  error messages)
- Grenzwacht -> Border Watch: fix stale German faction display name in
  reputation-display, reputation.service/controller, turn-in.service specs,
  and the vertical-slice seed spec test title
- Suedtor von Graufurt -> Graufurt South Gate: fix stale ASCII-transliterated
  German location name in hunting.service.spec.ts
- Aschenfelder(n) -> Ashen Fields: fix stale German location name/description
  in top-bar.component.spec.ts and context-panel.component.spec.ts (key
  identifiers left untouched)
- Fix 7 test titles still describing translated error messages as "German"
  across world/hunting/inventory/combat store specs
- README: update demo location names from German to their current English
  names (Graufurt South Gate, Burned Road)
- item-rarity.enum.ts: fix now-false comment claiming rarity labels are
  German; the frontend RARITY_LABELS map is English

Pure literal-string/comment substitutions; no keys, ids, or logic changed.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ACkMEDYiwtcfchqKkiUJNX

apps/web/src/app/features/inventory/inventory.store.spec.ts

@@ -132,7 +132,7 @@ describe('InventoryStore', () => {
     expect(worldStore.refreshCharacter).toHaveBeenCalledOnce();
   });
 
-  it('surfaces a German message for a known equip error', async () => {
+  it('surfaces an English message for a known equip error', async () => {
     await store.load();
     api.equipItem.mockReturnValue(
       throwError(() => new HttpErrorResponse({ error: { code: 'ITEM_NOT_EQUIPPABLE' }, status: 400 })),