feat: implement dynamic field labels for agent profile sections using backend-provided slugs

lib/features/agents/presentation/providers/agent_detail_provider.dart

@@ -292,6 +292,26 @@ class AgentDetailState {
     return '${'*' * (digits.length - 4)}${digits.substring(digits.length - 4)}';
   }
 
+  // ── Dynamic labels (fieldName from backend, with fallback) ──
+
+  String _labelForSlug(String slug, String fallback) {
+    for (final fv in fieldValues) {
+      if (fv.fieldSlug == slug && fv.fieldName.isNotEmpty) {
+        return fv.fieldName;
+      }
+    }
+    return fallback;
+  }
+
+  String get availabilityLabel =>
+      _labelForSlug('availability', 'Availability');
+
+  String get workEnvironmentLabel =>
+      _labelForSlug('preferred_work_environment', 'Preferred Work Environment');
+
+  String get bestExperienceLabel =>
+      _labelForSlug('best_experience', 'Best Experience');
+
   // ── Availability ──
 
   String get availabilityType {