refactor: restrict agent specializations to about_me_expertise field only

lib/features/agents/data/models/agent_profile.dart

@@ -153,21 +153,12 @@ class AgentProfile {
   }
 
   /// Get specializations / expertise from field values.
-  /// Matches web's getExpertiseTags slugs exactly.
+  /// Strictly reads about_me_expertise only (matches web + admin filter source).
   List<String> get specializations {
     final tags = <String>[];
-    // Must match web's expertiseFieldSlugs exactly (exact match, not contains)
-    const expertiseSlugs = [
-      'about_me_expertise',
-      'expertise_areas',
-      'specializations',
-      'areas_of_expertise',
-      'expertise',
-    ];
 
     for (final fv in fieldValues) {
-      final slug = fv.fieldSlug.toLowerCase();
-      if (!expertiseSlugs.contains(slug)) continue;
+      if (fv.fieldSlug.toLowerCase() != 'about_me_expertise') continue;
 
       if (fv.jsonValue is List) {
         for (final v in (fv.jsonValue as List)) {
@@ -187,16 +178,6 @@ class AgentProfile {
       }
     }
 
-    // Add from legacy specializations array
-    for (final spec in legacySpecializations) {
-      if (spec.isNotEmpty && !tags.contains(spec)) tags.add(spec);
-    }
-
-    // Add from languages array
-    for (final lang in languages) {
-      if (lang.isNotEmpty && !tags.contains(lang)) tags.add(lang);
-    }
-
     return tags;
   }