feat: add in-app admin navigation for whitelisted users

Detect admin access after login and expose a header button that opens /admin via client-side routing so the session stays unlocked when returning to the app.

Co-authored-by: Cursor <cursoragent@cursor.com>

client/src/i18n/locales/da.json

@@ -43,7 +43,8 @@
       "deviation": "Tabel over distraktioner",
       "logs": "Indlæg i logbogen",
       "stats": "Statistik",
-      "settings": "Indstillinger"
+      "settings": "Indstillinger",
+      "admin": "Admin"
     },
     "auth": {
       "welcome": "Velkommen til Kapteins Daagbok.",

client/src/i18n/locales/de.json

@@ -43,7 +43,8 @@
       "deviation": "Ablenkungstabelle",
       "logs": "Logbucheinträge",
       "stats": "Statistik",
-      "settings": "Einstellungen"
+      "settings": "Einstellungen",
+      "admin": "Admin"
     },
     "auth": {
       "welcome": "Willkommen bei Kapteins Daagbok",

client/src/i18n/locales/en.json

@@ -43,7 +43,8 @@
       "deviation": "Deviation Table",
       "logs": "Logbook Entries",
       "stats": "Statistics",
-      "settings": "Settings"
+      "settings": "Settings",
+      "admin": "Admin"
     },
     "auth": {
       "welcome": "Welcome to Kapteins Daagbok",

client/src/i18n/locales/nb.json

@@ -43,7 +43,8 @@
       "deviation": "Tabell over distraksjoner",
       "logs": "Loggbokoppføringer",
       "stats": "Statistikk",
-      "settings": "Innstillinger"
+      "settings": "Innstillinger",
+      "admin": "Admin"
     },
     "auth": {
       "welcome": "Velkommen til Kapteins Daagbok",

client/src/i18n/locales/sv.json

@@ -43,7 +43,8 @@
       "deviation": "Distraktionsbord",
       "logs": "Loggboksanteckningar",
       "stats": "Statistik",
-      "settings": "Inställningar"
+      "settings": "Inställningar",
+      "admin": "Admin"
     },
     "auth": {
       "welcome": "Välkommen till Kapteins Daagbok",