diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/ActivityLogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/ActivityLogController.java
index 06f94874..25f89ecf 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/ActivityLogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/ActivityLogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the activity log screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/AdoptionController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/AdoptionController.java
index 3ab3c712..bd761459 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/AdoptionController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/AdoptionController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the pet adoption management screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/AnalyticsController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/AnalyticsController.java
index 830ff827..60b031d1 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/AnalyticsController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/AnalyticsController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the analytics and reporting screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/AppointmentController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/AppointmentController.java
index a5a40c39..8d8b55b1 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/AppointmentController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/AppointmentController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the appointment scheduling screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
@@ -132,6 +138,10 @@ public class AppointmentController {
         loadAppointments();
     }
 
+    /**
+     * Fetches appointments from the API (filtered by store and optionally by employee)
+     * and updates both the table and the calendar event dots.
+     */
     private void loadAppointments(){
         new Thread(() -> {
             try{
@@ -165,6 +175,11 @@ public class AppointmentController {
         }).start();
     }
 
+    /**
+     * Sends a server-side search query and replaces the local list with results.
+     * Also refreshes calendar dots to match the filtered set.
+     * @param text the search query text
+     */
     private void applyFilter(String text) {
         String query = text == null || text.trim().isEmpty() ? null : text.trim();
         new Thread(() -> {
@@ -334,6 +349,10 @@ public class AppointmentController {
         return (selected != null && selected.getId() != null) ? selected.getId() : null;
     }
 
+    /**
+     * Applies the client-side filters (calendar date selection and status dropdown)
+     * on top of whatever the server already returned.
+     */
     private void applyFilterPredicate() {
         String selectedStatus = cbStatusFilter.getValue();
         filtered.setPredicate(apt -> {
@@ -372,6 +391,12 @@ public class AppointmentController {
         );
     }
 
+    /**
+     * Normalizes the status string from the API to title case for display.
+     * Handles inconsistencies like "cancelled" vs "canceled".
+     * @param status raw status from the server
+     * @return normalized display string
+     */
     private String normalizeAppointmentStatus(String status) {
         if (status == null) {
             return "Booked";
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/ChatController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/ChatController.java
index 3ba9e995..66ef1f47 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/ChatController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/ChatController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the in-app messaging screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
@@ -105,6 +111,8 @@ public class ChatController {
         lvActiveConversations.setItems(activeConversations);
         lvClosedConversations.setItems(closedConversations);
 
+        // The two lists share a single selection — picking one clears the other.
+        // selectionChanging flag prevents the clear from triggering a feedback loop.
         lvActiveConversations.getSelectionModel().selectedItemProperty().addListener((obs, oldVal, newVal) -> {
             if (newVal != null && !selectionChanging) {
                 selectionChanging = true;
@@ -304,6 +312,11 @@ public class ChatController {
         btnAttachment.setStyle("-fx-background-color: #e2e8f0; -fx-background-radius: 12; -fx-text-fill: #475569; -fx-cursor: hand;");
     }
 
+    /**
+     * Configures a conversation list with custom cells showing title, preview, and status.
+     * Highlights conversations that need pickup or reply in red.
+     * @param lv the ListView to configure
+     */
     private void setupConversationListView(ListView<ConversationResponse> lv) {
         lv.setFixedCellSize(CHAT_CELL_HEIGHT);
         lv.setCellFactory(list -> new ListCell<>() {
@@ -453,6 +466,12 @@ public class ChatController {
         scrollMessagesToBottom();
     }
 
+    /**
+     * Handles an incoming message from the WebSocket.
+     * Only adds it to the view if it belongs to the currently selected conversation
+     * and hasn't already been rendered (dedup by message ID).
+     * @param message the incoming message
+     */
     private void appendMessageIfSelected(MessageResponse message) {
         try {
             upsertConversationForMessage(message);
@@ -474,6 +493,11 @@ public class ChatController {
         }
     }
 
+    /**
+     * Inserts or updates a conversation in the list and re-sorts by last activity.
+     * Called when the WebSocket pushes a conversation update (e.g. status change).
+     * @param conversation the updated conversation from the server
+     */
     private void upsertConversation(ConversationResponse conversation) {
         Optional<ConversationResponse> existing = conversations.stream()
                 .filter(item -> item.getId().equals(conversation.getId()))
@@ -507,6 +531,10 @@ public class ChatController {
                 });
     }
 
+    /**
+     * Re-selects the previously selected conversation after the list is rebuilt.
+     * Needed because refreshSections() replaces all items, which clears the selection.
+     */
     private void restoreSelection() {
         if (selectedConversation == null) {
             return;
@@ -528,6 +556,12 @@ public class ChatController {
                 });
     }
 
+    /**
+     * Builds a single chat bubble with avatar, author label, text, optional
+     * image/attachment preview, and timestamp. Own messages go right, others left.
+     * @param message the message to render
+     * @return the bubble wrapped in an HBox
+     */
     private HBox createMessageBubble(MessageResponse message) {
         boolean mine = message.getSenderId() != null && message.getSenderId().equals(UserSession.getInstance().getUserId());
 
@@ -609,6 +643,13 @@ public class ChatController {
         return container;
     }
 
+    /**
+     * Figures out the display label for a message sender.
+     * Shows "You" for own messages, "AI Bot" for bot messages, and
+     * "Staff" or "Customer" for everyone else.
+     * @param message the message to resolve
+     * @return the author display name
+     */
     private String resolveAuthorLabel(MessageResponse message) {
         if ("BOT".equalsIgnoreCase(message.getSenderRole())) {
             return message.getSenderDisplayName() != null && !message.getSenderDisplayName().isBlank()
@@ -630,6 +671,12 @@ public class ChatController {
         return customerLabel != null ? customerLabel : "Customer #" + conversation.getCustomerId();
     }
 
+    /**
+     * Builds the small status line under each conversation in the sidebar.
+     * Shows assignment state (Automated, Assigned, Takeover requested, etc.) and time.
+     * @param conversation the conversation to summarize
+     * @return a short status string like "Assigned · Apr 10, 14:30"
+     */
     private String buildConversationMeta(ConversationResponse conversation) {
         String updated = conversation.getUpdatedAt() == null ? "" : TIME_FORMATTER.format(conversation.getUpdatedAt());
         if ("CLOSED".equals(conversation.getStatus())) {
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/CouponController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/CouponController.java
index af418826..3dd02612 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/CouponController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/CouponController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the coupon management screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/CustomerAccountsController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/CustomerAccountsController.java
index eddf0df9..3f87b773 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/CustomerAccountsController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/CustomerAccountsController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the customer accounts screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/InventoryController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/InventoryController.java
index a724a367..c95dd62d 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/InventoryController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/InventoryController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the inventory management screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/LoginController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/LoginController.java
index 6c3427ea..f7988cf3 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/LoginController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/LoginController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the login screen and handles authentication.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/MainLayoutController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/MainLayoutController.java
index 11d8cceb..1ba56945 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/MainLayoutController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/MainLayoutController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the main layout with sidebar navigation.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
@@ -339,6 +345,10 @@ public class MainLayoutController {
         }
     }
 
+    /**
+     * Fetches the current user info from the server on a background thread
+     * and updates the sidebar avatar and display name.
+     */
     private void refreshProfileHeader() {
         new Thread(() -> {
             try {
@@ -376,6 +386,12 @@ public class MainLayoutController {
         }
     }
 
+    /**
+     * Renders the avatar in the sidebar. Shows the uploaded image if available,
+     * otherwise shows a colored circle with the user's initials.
+     * @param displayName used to generate initials as a fallback
+     * @param avatarImage the user's profile image, or null for the initials fallback
+     */
     private void renderAvatar(String displayName, Image avatarImage) {
         Circle border = new Circle(29);
         border.setFill(Color.web("#dbe4ee"));
@@ -427,6 +443,11 @@ public class MainLayoutController {
         alert.showAndWait();
     }
 
+    /**
+     * Shows or hides sidebar buttons based on the user's role.
+     * Admin gets inventory, suppliers, staff accounts, etc.
+     * Also kicks off chat WebSocket subscription in the background.
+     */
     private void applyRBAC() {
         UserSession session = UserSession.getInstance();
 
@@ -498,6 +519,10 @@ public class MainLayoutController {
         }).start();
     }
 
+    /**
+     * Swaps the main content area to a different view.
+     * @param fxmlFile the FXML filename inside the modelviews folder
+     */
     private void loadView(String fxmlFile) {
         try {
             FXMLLoader loader = new FXMLLoader(getClass().getResource("/org/example/petshopdesktop/modelviews/" + fxmlFile));
@@ -551,6 +576,11 @@ public class MainLayoutController {
         }
     }
 
+    /**
+     * Maps EXIF orientation tag values to rotation angles.
+     * @param orientation the EXIF orientation value (1-8)
+     * @return degrees to rotate the image
+     */
     private double exifOrientationToAngle(int orientation) {
         return switch (orientation) {
             case 3 -> 180;
@@ -560,6 +590,13 @@ public class MainLayoutController {
         };
     }
 
+    /**
+     * Manually reads the EXIF orientation tag from raw JPEG bytes.
+     * Walks the JPEG markers to find APP1 (Exif), then parses the TIFF IFD
+     * entries looking for tag 0x0112 (orientation).
+     * @param data raw JPEG image bytes
+     * @return the orientation value (1-8), defaults to 1 if not found
+     */
     private int readExifOrientation(byte[] data) {
         try {
             if (data.length < 2 || (data[0] & 0xFF) != 0xFF || (data[1] & 0xFF) != 0xD8) return 1;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/PetController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/PetController.java
index 35201c45..a0eaf3c5 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/PetController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/PetController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the pet listings screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/ProductController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/ProductController.java
index 6a66c865..b5008eab 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/ProductController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/ProductController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the product catalog screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.animation.KeyFrame;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/ProductSupplierController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/ProductSupplierController.java
index 8060a68f..7a79ea82 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/ProductSupplierController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/ProductSupplierController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the product-supplier linking screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/PurchaseOrderController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/PurchaseOrderController.java
index ca688856..29d40c89 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/PurchaseOrderController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/PurchaseOrderController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the purchase order management screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/SaleController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/SaleController.java
index 7e71dc32..dc5dadd3 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/SaleController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/SaleController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the sales and transactions screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.collections.FXCollections;
@@ -427,6 +433,10 @@ public class SaleController {
         new Thread(task).start();
     }
 
+    /**
+     * Shows or hides the create-sale panel based on role.
+     * Admins get read-only view; staff can create sales and process refunds.
+     */
     private void applyRoleMode() {
         boolean isAdmin = UserSession.getInstance().isAdmin();
         vbCreateSale.setVisible(!isAdmin);
@@ -440,6 +450,12 @@ public class SaleController {
         refreshSales(false);
     }
 
+    /**
+     * Fetches all sales from the API and flattens them into per-item line rows.
+     * Applies any active store filter. Discounts are distributed proportionally
+     * across line items using a ratio of total to subtotal.
+     * @param showErrorDialog whether to show error dialogs on failure
+     */
     private void refreshSales(boolean showErrorDialog) {
         btnRefresh.setDisable(true);
         Task<List<SaleLineItem>> task = new Task<List<SaleLineItem>>() {
@@ -456,6 +472,7 @@ public class SaleController {
                         : "";
 
                     if (sale.getItems() != null && !sale.getItems().isEmpty()) {
+                        // Spread the discount evenly across line items via a ratio
                         double saleSubtotal = sale.getSubtotalAmount() != null ? Math.abs(sale.getSubtotalAmount().doubleValue()) : 0;
                         double saleActualTotal = sale.getTotalAmount() != null ? Math.abs(sale.getTotalAmount().doubleValue()) : 0;
                         double discountRatio = saleSubtotal > 0 ? saleActualTotal / saleSubtotal : 1.0;
@@ -816,6 +833,12 @@ public class SaleController {
         new Thread(task).start();
     }
 
+    /**
+     * Converts a SaleResponse from the API into a SaleDetail for the detail dialog.
+     * Distributes discounts across line items the same way refreshSales does.
+     * @param sale the API response
+     * @return the mapped detail object
+     */
     private SaleDetail mapToSaleDetail(SaleResponse sale) {
         ObservableList<SaleDetail.SaleDetailItem> items = FXCollections.observableArrayList();
         double saleSubtotal = sale.getSubtotalAmount() != null ? Math.abs(sale.getSubtotalAmount().doubleValue()) : 0;
@@ -858,6 +881,10 @@ public class SaleController {
         );
     }
 
+    /**
+     * Recalculates the cart summary: subtotal, coupon discount, loyalty discount, and final total.
+     * Also updates the "points to earn" preview for the selected customer.
+     */
     private void updateCartTotal() {
         BigDecimal subtotal = BigDecimal.valueOf(cartItems.stream().mapToDouble(SaleCartItem::getTotal).sum());
         BigDecimal couponDiscount = calculateCouponDiscount(subtotal);
@@ -900,6 +927,12 @@ public class SaleController {
         }
     }
 
+    /**
+     * Calculates how much the coupon takes off. Percentage coupons use the
+     * subtotal; fixed-amount coupons are capped at the subtotal.
+     * @param subtotal the cart subtotal before discounts
+     * @return the discount amount
+     */
     private BigDecimal calculateCouponDiscount(BigDecimal subtotal) {
         if (appliedCoupon == null) {
             return BigDecimal.ZERO;
@@ -911,6 +944,11 @@ public class SaleController {
         }
     }
 
+    /**
+     * Calculates loyalty point discount. Each point is worth $0.05.
+     * @param subtotalAfterCoupon the amount after coupon discount
+     * @return the loyalty discount amount
+     */
     private BigDecimal calculateLoyaltyDiscount(BigDecimal subtotalAfterCoupon) {
         if (!chkUseLoyaltyPoints.isSelected() || selectedCustomerData == null) {
             return BigDecimal.ZERO;
@@ -919,6 +957,13 @@ public class SaleController {
         return BigDecimal.valueOf(pointsToUse).multiply(BigDecimal.valueOf(0.05));
     }
 
+    /**
+     * Figures out how many loyalty points to redeem. Uses up to the customer's
+     * full balance, but never more than would cover the remaining total.
+     * The multiplier of 20 means 20 points = $1.00 of discount.
+     * @param subtotalAfterCoupon amount left after coupon
+     * @return number of points to use
+     */
     private int calculatePointsToUse(BigDecimal subtotalAfterCoupon) {
         if (selectedCustomerData == null || selectedCustomerData.getLoyaltyPoints() == null) {
             return 0;
@@ -998,6 +1043,10 @@ public class SaleController {
         chkUseLoyaltyPoints.setDisable(disabled);
     }
 
+    /**
+     * Applies the combined text search, payment type, refund status, and customer filters.
+     * @param filter the text search input
+     */
     private void applySalesFilter(String filter) {
         String f = filter == null ? "" : filter.trim().toLowerCase();
         String selectedPayment = cbFilterPayment.getValue();
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/ServiceController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/ServiceController.java
index 10acb9ed..ccc7c309 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/ServiceController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/ServiceController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the services management screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/StaffAccountsController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/StaffAccountsController.java
index 36c7378b..b8abc026 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/StaffAccountsController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/StaffAccountsController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the staff accounts screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/SupplierController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/SupplierController.java
index c6120d15..132cd54f 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/SupplierController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/SupplierController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the supplier management screen.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/AdoptionDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/AdoptionDialogController.java
index 39947fcc..59ced6ac 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/AdoptionDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/AdoptionDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog for creating or editing an adoption.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/AppointmentDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/AppointmentDialogController.java
index 1b5530cd..a3934850 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/AppointmentDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/AppointmentDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog for creating or editing an appointment.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/CouponDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/CouponDialogController.java
index 21fbc521..d477d543 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/CouponDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/CouponDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog for creating or editing a coupon.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.collections.FXCollections;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/CustomerEditDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/CustomerEditDialogController.java
index 92c800e3..ddf4ffcf 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/CustomerEditDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/CustomerEditDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog for editing customer details.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/InventoryDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/InventoryDialogController.java
index 2aa797e4..1ee51acb 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/InventoryDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/InventoryDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog for adjusting inventory levels.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/PetDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/PetDialogController.java
index ea4e853a..9ae1c11d 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/PetDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/PetDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog for adding or editing a pet.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ProductDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ProductDialogController.java
index 2a51e42a..8027b863 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ProductDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ProductDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog for adding or editing a product.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.collections.FXCollections;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ProductSupplierDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ProductSupplierDialogController.java
index 8e2ef094..b3738276 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ProductSupplierDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ProductSupplierDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog for linking a product to a supplier.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/PurchaseOrderDetailsDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/PurchaseOrderDetailsDialogController.java
index ff597d36..b609ba9a 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/PurchaseOrderDetailsDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/PurchaseOrderDetailsDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog that shows purchase order details.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.fxml.FXML;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/RefundDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/RefundDialogController.java
index 11a186db..3de67979 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/RefundDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/RefundDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog for processing a refund.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.collections.FXCollections;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/SaleDetailDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/SaleDetailDialogController.java
index 4774c14d..144ae5e5 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/SaleDetailDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/SaleDetailDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog that shows sale details.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.fxml.FXML;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ServiceDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ServiceDialogController.java
index 26f13b0f..b69e008a 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ServiceDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/ServiceDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog for creating or editing a service.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/StaffEditDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/StaffEditDialogController.java
index 86a8603a..12cd832c 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/StaffEditDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/StaffEditDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog for editing staff member details.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/StaffRegisterDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/StaffRegisterDialogController.java
index 04fc74bf..b82bdcf5 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/StaffRegisterDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/StaffRegisterDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog for registering a new staff member.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.application.Platform;
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/SupplierDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/SupplierDialogController.java
index 44131a6c..173f1194 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/SupplierDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/SupplierDialogController.java
@@ -1,3 +1,9 @@
+/*
+ * Controls the dialog for adding or editing a supplier.
+ *
+ * Author: Harkamal
+ * Date: April 2026
+ */
 package org.example.petshopdesktop.controllers.dialogcontrollers;
 
 import javafx.event.EventHandler;