feat: complete English wiki — all pages bilingual (DE + EN)
New English pages (8):
Installation-EN, Configuration-EN, Permissions-EN, Workflow-EN,
Mod-Commands-EN, Ticket-Commands-EN, Voice-Commands-EN,
Preview-Commands-EN
_Sidebar.md updated — English section now links to all pages:
Setup: Installation-EN, Configuration-EN
Commands: Mod-Commands-EN, Ticket-Commands-EN,
Voice-Commands-EN, Preview-Commands-EN
Staff: Permissions-EN, Workflow-EN
Wiki now 100% bilingual: every German page has an English equivalent.
Total: 20 English module/setup pages + bilingual Home + Sidebar.
