feat: Add conversations summary CSV export (#13110)

# Pull Request Template

## Description

This PR adds support for exporting conversation summary reports as CSV.
Previously, the Conversations report incorrectly showed an option to
download agent reports; this has now been fixed to export
conversation-level data instead.

Fixes
https://linear.app/chatwoot/issue/CW-6176/conversation-reports-export-button-exports-agent-reports-instead

## Type of change

- [x] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)

## How Has This Been Tested?

### Screenshot
<img width="1859" height="1154" alt="image"
src="https://github.com/user-attachments/assets/419d26f4-fda9-4782-aea6-55ffad0c37ab"
/>



## Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [ ] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

app/javascript/dashboard/store/modules/reports.js

@@ -234,6 +234,19 @@ export const actions = {
         console.error(error);
       });
   },
+  downloadConversationsSummaryReports(_, reportObj) {
+    return Report.getConversationsSummaryReports(reportObj)
+      .then(response => {
+        downloadCsvFile(reportObj.fileName, response.data);
+        AnalyticsHelper.track(REPORTS_EVENTS.DOWNLOAD_REPORT, {
+          reportType: 'conversations_summary',
+          businessHours: reportObj?.businessHours,
+        });
+      })
+      .catch(error => {
+        console.error(error);
+      });
+  },
   downloadLabelReports(_, reportObj) {
     return Report.getLabelReports(reportObj)
       .then(response => {

app/javascript/dashboard/store/modules/specs/reports/actions.spec.js

@@ -201,4 +201,24 @@ describe('#actions', () => {
       );
     });
   });
+
+  describe('#downloadConversationsSummaryReports', () => {
+    it('open CSV download prompt if API is success', async () => {
+      const data = `Conversations,Messages received,Messages sent,Avg first response time,Avg resolution time,Resolution count,Avg customer waiting time
+      217,323,623,23 hours 22 minutes,179 days 18 hours,30,48 days 4 hours`;
+      axios.get.mockResolvedValue({ data });
+      const param = {
+        from: 1631039400,
+        to: 1635013800,
+        fileName: 'conversations-summary-report-24-10-2021.csv',
+      };
+      actions.downloadConversationsSummaryReports(1, param);
+      await flushPromises();
+
+      expect(DownloadHelper.downloadCsvFile).toBeCalledWith(
+        param.fileName,
+        data
+      );
+    });
+  });
 });