fix: add deduplication check to SaveReportAsync

Prevent duplicate reports by checking if a report already exists
for the same incidentId before saving. Returns bool to indicate
if the report was saved (true) or skipped as duplicate (false).

Worker now logs warnings when duplicates are detected, helping
identify the root cause of duplicate report generation.

Author: Steve Hansen

src/FleetClaim.Core/Geotab/AddInDataRepository.cs

@@ -14,7 +14,11 @@ public interface IAddInDataRepository
     Task<WorkerState?> GetWorkerStateAsync(IGeotabApi api, string database, CancellationToken ct = default);
     Task SaveWorkerStateAsync(IGeotabApi api, string database, WorkerState state, CancellationToken ct = default);
 
-    Task SaveReportAsync(IGeotabApi api, IncidentReport report, CancellationToken ct = default);
+    /// <summary>
+    /// Saves a report, checking for duplicates by incidentId.
+    /// Returns true if saved, false if a report already exists for this incident.
+    /// </summary>
+    Task<bool> SaveReportAsync(IGeotabApi api, IncidentReport report, CancellationToken ct = default);
     Task SaveRequestAsync(IGeotabApi api, ReportRequest request, CancellationToken ct = default);
     Task UpdateRequestStatusAsync(IGeotabApi api, string requestId, ReportRequestStatus status, string? error = null, int? incidentsFound = null, int? reportsGenerated = null, string? errorMessage = null, CancellationToken ct = default);
 
@@ -126,12 +130,23 @@ public async Task SaveWorkerStateAsync(IGeotabApi api, string database, WorkerSt
         }
     }
 
-    public async Task SaveReportAsync(IGeotabApi api, IncidentReport report, CancellationToken ct = default)
+    public async Task<bool> SaveReportAsync(IGeotabApi api, IncidentReport report, CancellationToken ct = default)
     {
+        // Check if a report already exists for this incident (deduplication)
+        var whereClause = $"type == \"report\" && payload.incidentId == \"{report.IncidentId}\"";
+        var existing = await GetFilteredAddInDataAsync(api, whereClause, ct);
+        
+        if (existing.Count > 0)
+        {
+            // Report already exists for this incident - skip to prevent duplicates
+            return false;
+        }
+        
         // Compact the report to fit within AddInData 10KB limit
         var compactedReport = CompactReportForStorage(report);
         var wrapper = AddInDataWrapper.ForReport(compactedReport);
         await AddNewRecordAsync(api, wrapper, ct);
+        return true;
     }
 
     /// <summary>

src/FleetClaim.Worker/IncidentPollerWorker.cs

@@ -743,10 +743,19 @@ private async Task GenerateAndSaveReportAsync(
         var report = await _reportGenerator.GenerateReportAsync(api, incident, database, ct);
         report.Source = source;  // Set the source based on how the report was triggered
 
-        await _repository.SaveReportAsync(api, report, ct);
+        var wasSaved = await _repository.SaveReportAsync(api, report, ct);
 
-        _logger.LogInformation("Saved report {ReportId} for incident {IncidentId}",
-            report.Id, incident.Id);
+        if (wasSaved)
+        {
+            _logger.LogInformation("Saved report {ReportId} for incident {IncidentId}",
+                report.Id, incident.Id);
+        }
+        else
+        {
+            _logger.LogWarning("Skipped duplicate report for incident {IncidentId} - report already exists",
+                incident.Id);
+            return; // Don't send notifications for duplicates
+        }
 
         // Send notifications if configured
         if (report.Severity >= config.SeverityThreshold)