Docs, gettext, and remaining test updates

- groups-architecture and membership-fee-architecture docs
- Gettext: add/correct German for authorization and membership fee type
- membership_fee_helpers_test and membership_fee_status_test adjustments

docs/groups-architecture.md

@@ -4,7 +4,7 @@
 **Feature:** Groups Management  
 **Version:** 1.0  
 **Last Updated:** 2025-01-XX  
-**Status:** Architecture Design - Ready for Implementation
+**Status:** ✅ Implemented (authorization: see [roles-and-permissions-architecture.md](./roles-and-permissions-architecture.md))
 
 ---
 
@@ -412,12 +412,14 @@ lib/
 
 ## Authorization
 
+**Status:** ✅ Implemented. Group and MemberGroup resource policies and PermissionSets are in place. See [roles-and-permissions-architecture.md](./roles-and-permissions-architecture.md) for the full permission matrix and policy patterns.
+
 ### Permission Model (MVP)
 
-**Resource:** `groups`
+**Resource:** `Group` (and `MemberGroup`)
 
 **Actions:**
-- `read` - View groups (all users with member read permission)
+- `read` - View groups (all permission sets)
 - `create` - Create groups (admin only)
 - `update` - Edit groups (admin only)
 - `destroy` - Delete groups (admin only)