Adds comprehensive customer detail page with dynamic features

Develops detailed customer profile view with multiple sections including overview, statistics, journal, appointments, and activity tracking

Implements interactive UI components for customer management
Includes dynamic tab switching, editable profile sections, and activity timeline

PlanTempus.Application/wwwroot/css/COMPONENT-CATALOG.md

@@ -78,16 +78,26 @@ Standard icon wrapper (40×40px cirkel):
 | `swp-card-header` | Card header wrapper | Flex, space-between, border-bottom |
 | `swp-card-title` | Card title med ikon | Flex, icon + text |
 | `swp-section-action` | Action link i header | Teal, clickable |
-| `swp-section-label` | Subsection label (inde i card) | Uppercase, 11px, border-bottom |
+| `swp-section-label` | Subsection label (KUN til sekundære sektioner inde i card, ALDRIG som card header) | Uppercase, 11px, border-bottom |
 | `swp-card-content` | Card indhold | Block |
 
 ### Card Header Eksempler
 
-**Standard card header (ANBEFALET):**
+**VIGTIGT:** Brug ALTID `swp-card-header` + `swp-card-title` som første element i et card.
+
+❌ **FORKERT - brug IKKE `swp-section-label` som card header:**
+```html
+<swp-card>
+    <swp-section-label>Kontaktoplysninger</swp-section-label>
+    <!-- content -->
+</swp-card>
+```
+
+✅ **KORREKT - brug `swp-card-header` + `swp-card-title`:**
 ```html
 <swp-card>
     <swp-card-header>
-        <swp-card-title>Kontakter</swp-card-title>
+        <swp-card-title>Kontaktoplysninger</swp-card-title>
     </swp-card-header>
     <!-- content -->
 </swp-card>
@@ -117,7 +127,7 @@ Standard icon wrapper (40×40px cirkel):
 </swp-card>
 ```
 
-**Subsection label (inde i card):**
+**Subsection label (KUN til sekundære sektioner inde i card):**
 ```html
 <swp-card>
     <swp-card-header>
@@ -130,6 +140,8 @@ Standard icon wrapper (40×40px cirkel):
 </swp-card>
 ```
 
+**HUSK:** `swp-section-label` må ALDRIG bruges som erstatning for `swp-card-header`!
+
 ---
 
 ## Stats Components (stats.css)

PlanTempus.Application/wwwroot/css/components.css

@@ -1353,6 +1353,11 @@ swp-detail-grid {
   grid-template-columns: repeat(2, 1fr);
   gap: var(--card-gap);
   align-items: start;
+
+  /* Full width cards span both columns */
+  & > .full-width {
+    grid-column: 1 / -1;
+  }
 }
 
 /* ===========================================