Adds comprehensive customers list and management components

Introduces customer-related view components for table and row display
Implements mock data loading and customer list rendering
Adds localization support for customer-related text
Enhances UI with detailed customer information and interactions

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

@@ -562,5 +562,54 @@
         "dailysummary": "Email med daglig oversigt"
       }
     }
+  },
+  "customers": {
+    "title": "Kunder",
+    "subtitle": "Administrer kunder og kundekort",
+    "searchPlaceholder": "Søg kunde (navn, telefon, email...)",
+    "export": "Eksporter",
+    "create": "Ny kunde",
+    "emptySearch": "Ingen kunder matcher din søgning",
+    "column": {
+      "name": "Navn",
+      "phone": "Telefon",
+      "email": "Email",
+      "visits": "Besøg",
+      "lastVisit": "Sidste",
+      "hairdresser": "Frisør",
+      "created": "Oprettet",
+      "tags": "Tags"
+    },
+    "stats": {
+      "total": "Total kunder",
+      "newThisMonth": "Nye denne måned",
+      "avgVisits": "Gns. besøg"
+    },
+    "drawer": {
+      "title": "Kundekort",
+      "visits": "Besøg",
+      "avgInterval": "Gns. interval",
+      "preferredHairdresser": "Foretrukken frisør",
+      "contactInfo": "Kontaktoplysninger",
+      "phone": "Telefon",
+      "email": "Email",
+      "address": "Adresse",
+      "zipCity": "Postnr + By",
+      "marketing": "Marketing",
+      "emailMarketing": "Email marketing",
+      "smsMarketing": "SMS marketing",
+      "profile": "Profil",
+      "hairType": "Hårtype",
+      "porosity": "Porøsitet",
+      "preference": "Præference",
+      "warnings": "Advarsler",
+      "revenueChart": "Omsætning (sidste 6 mdr)",
+      "services": "Services",
+      "products": "Produkter",
+      "recentNotes": "Seneste noter",
+      "noteType": "Note",
+      "colorFormula": "Farveformel",
+      "seeAllNotes": "Se alle noter →"
+    }
   }
 }