Adds comprehensive customer detail view components

Implements full customer detail page with multiple feature-rich components including overview, economy, statistics, journal, appointments, giftcards, and activity sections

Creates reusable ViewComponents for different customer detail aspects with robust data modeling and presentation logic

PlanTempus.Application/Features/Localization/Translations/da.json

@@ -656,8 +656,52 @@
       "seeAllNotes": "Se alle noter →"
     },
     "detail": {
+      "back": "Tilbage til kunder",
+      "delete": "Slet kunde",
+      "save": "Gem",
       "tabs": {
+        "overview": "Oversigt",
+        "economy": "Økonomi",
+        "statistics": "Statistik",
+        "journal": "Journal",
+        "appointments": "Aftaler",
+        "giftcards": "Gavekort",
         "activitylog": "Aktivitetslog"
+      },
+      "visits": "besøg",
+      "interval": "dage interval",
+      "preferredHairdresser": "foretrukken frisør",
+      "totalRevenue": "total omsætning",
+      "bookingAllowed": "Booking tilladt",
+      "bookingBlocked": "Booking blokeret",
+      "contactInfo": "Kontaktoplysninger",
+      "phone": "Telefon",
+      "email": "Email",
+      "address": "Adresse",
+      "zipCity": "Postnr + By",
+      "profile": "Profil",
+      "marketing": "Marketing",
+      "emailMarketing": "Email marketing",
+      "smsMarketing": "SMS marketing",
+      "paymentSettings": "Betalingsindstillinger",
+      "requirePrepayment": "Kræv forudbetaling",
+      "allowPartialPayment": "Tillad delvis betaling",
+      "preferences": "Præferencer",
+      "preferredDay": "Foretrukken dag",
+      "specialRequests": "Specielle ønsker",
+      "warnings": "Advarsler",
+      "groupAndRelations": "Kundegruppe & Relationer",
+      "economy": {
+        "thisYear": "I år ({0})",
+        "lastYear": "Sidste år",
+        "avgPerVisit": "Gns. pr. besøg",
+        "avgPerMonth": "Gns. pr. måned",
+        "revenueOverTime": "Omsætning over tid",
+        "services": "Services",
+        "products": "Produkter",
+        "purchaseHistory": "Købshistorik",
+        "seeAll": "Se alle transaktioner",
+        "noData": "Ingen økonomiske data tilgængelige"
       }
     }
   }