Improve email subject configuration documentation

- Clarify subject template placeholders in system.xml comment
- Update README.md to be more explicit about {{month}} and {{year}} usage
- Add example in copilot-instructions.md for better clarity

.github/copilot-instructions.md

@@ -93,7 +93,7 @@ SELECT * FROM cron_schedule WHERE job_code = 'shopkeeper_vendorsalesreport_month
 ### Configuration
 - **Email Recipients**: Must be comma-separated, validated before sending
 - **Order Status**: Stored as comma-separated string, converted to array by helper
-- **Subject Templates**: Support `{{month}}` and `{{year}}` placeholders
+- **Subject Templates**: Support `{{month}}` and `{{year}}` placeholders for dynamic email subjects (e.g., "Monthly Report - {{month}} {{year}}")
 
 ### Performance
 - **Raw SQL**: Used for performance with large datasets - avoid ORM for report queries

README.md

@@ -66,7 +66,7 @@ php bin/magento cache:flush
 #### Email Settings
 - **Enable Email**: Enable/disable email delivery
 - **Email Recipients**: Comma-separated list of email addresses
-- **Email Subject**: Subject line for automated emails (supports {{month}} and {{year}} placeholders)
+- **Email Subject**: Subject line for automated emails (use {{month}} and {{year}} placeholders for dynamic values)
 - **Email Sender**: Choose which store email identity to use as sender
 
 ### Example Configuration

etc/adminhtml/system.xml

@@ -37,7 +37,7 @@
                 </field>
                 <field id="subject" translate="label comment" type="text" sortOrder="30" showInDefault="1" showInWebsite="0" showInStore="0">
                     <label>Email Subject</label>
-                    <comment>Subject line for automated report emails. Use {{month}} and {{year}} for dynamic values.</comment>
+                    <comment>Subject line for automated report emails. Use {{month}} and {{year}} placeholders for dynamic values (e.g., "Monthly Report - {{month}} {{year}}").</comment>
                     <depends>
                         <field id="enabled">1</field>
                     </depends>