🎯 RESTORE: Enhanced admin user management functionality

✅ Added user search functionality to admin users page
✅ Created comprehensive user detail template with:
   - Complete user information display
   - User action buttons (activate/deactivate/delete)
   - Quotation history for each user
   - Improved tooltips and responsive design
✅ Enhanced admin users table with better action buttons
✅ Added proper error handling and confirmation dialogs

SAFE: Only affects admin pages, calculator functionality unchanged

src/app/routes/admin.py

@@ -57,9 +57,23 @@ def dashboard():
 def users():
     try:
         page = request.args.get('page', 1, type=int)
+        search = request.args.get('search', '').strip()
         per_page = 20
         
-        users = User.query.order_by(User.created_at.desc()).paginate(
+        # Build query with search functionality
+        query = User.query
+        
+        if search:
+            # Search by username or email (case-insensitive)
+            search_filter = f"%{search.lower()}%"
+            query = query.filter(
+                db.or_(
+                    User.username.ilike(search_filter),
+                    User.email.ilike(search_filter)
+                )
+            )
+        
+        users = query.order_by(User.created_at.desc()).paginate(
             page=page, per_page=per_page, error_out=False
         )
         
@@ -229,7 +243,7 @@ def delete_quotation():
     if not request.is_json:
         return jsonify({'error': 'Invalid request format'}), 400
         
-        data = request.get_json()
+    data = request.get_json()
     quotation_id = data.get('quotation_id')
         
     if not quotation_id: