feat(module-grants): Stufe Verwalten in Freigaben-Matrix und Benutzerdetails, Doku und Changelog

- Matrix und Benutzerdetails liefern und zeigen die Stufe, Auswahlfeld Benutzen/Verwalten
- Gruppen mit Verwalten sind in den Benutzerdetails markiert
- Administrationshandbuch, Anwenderanleitung und Changelog beschreiben die Stufen

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

apps/web/src/messages/en.json

@@ -553,6 +553,8 @@
         "noInheritance": "–",
         "noActiveModules": "No modules are activated for this tenant.",
         "directCheckboxLabel": "{granted, select, true {Grant} other {Revoke}} {module} directly for {user}",
+        "directLevelLabel": "Level of the direct grant of {module} for {user}",
+        "manageMarker": "Manage",
         "saveError": "Could not save grant. Please try again."
       },
       "errors": {
@@ -730,7 +732,10 @@
         "body": "This group has {memberCount, plural, one {# member} other {# members}} and {grantCount, plural, one {# module grant} other {# module grants}}. Affected users will lose access unless they have it another way. This action cannot be undone."
       },
       "grants": {
-        "matrixCheckboxLabel": "{granted, select, true {Grant} other {Revoke}} {module} for group {group}"
+        "matrixCheckboxLabel": "{granted, select, true {Grant} other {Revoke}} {module} for group {group}",
+        "levelUse": "Use",
+        "levelManage": "Manage",
+        "levelSelectLabel": "Level for {module} in group {group}"
       }
     },
     "customModules": {
@@ -860,7 +865,8 @@
       "searchPlaceholder": "Search modules or groups...",
       "emptyModules": "No modules are activated for this tenant yet. Activate a module under Modules first.",
       "emptyModulesLink": "Go to Modules",
-      "adminNote": "ADMIN and SUPER_ADMIN always have access to all active modules — this matrix only applies to the USER role.",
+      "levelExplanation": "“Use”: open the module and work with it. “Manage”: additionally change the settings of this module. Only administrators may grant access and activate modules. If someone has access through several routes, the higher level applies.",
+      "adminNote": "Administrators always have access to all active modules and may change their settings — this matrix only affects users without administrator rights.",
       "saveError": "Could not save grant. Please try again.",
       "noSearchResults": "No match for \"{search}\" — neither in the modules nor in the groups."
     },