security: Add Discord mention sanitization to prevent abuse

test-security.ps1

@@ -0,0 +1,43 @@
+# Test Error Reporting Security
+
+Write-Host "Testing Discord mention sanitization..." -ForegroundColor Cyan
+Write-Host ""
+
+$apiUrl = "https://light-rewards-bot.vercel.app/api/report-error"
+
+# Test avec des mentions Discord malveillantes
+$payload = @{
+    error = "Test @everyone @here error with <@123456789> user mention"
+    stack = "at testFunction <@&987654321> role mention`n    at main <#555555555> channel"
+    context = @{
+        version = "3.5.6"
+        platform = "win32"
+        arch = "x64"
+        nodeVersion = "v22.0.0"
+        timestamp = [DateTime]::UtcNow.ToString("yyyy-MM-ddTHH:mm:ss.fffZ")
+        botMode = "SECURITY_TEST"
+    }
+} | ConvertTo-Json -Depth 10
+
+Write-Host "Payload with malicious mentions:" -ForegroundColor Yellow
+Write-Host $payload -ForegroundColor Gray
+Write-Host ""
+
+try {
+    $response = Invoke-RestMethod -Uri $apiUrl -Method Post -Body $payload -ContentType "application/json" -TimeoutSec 15
+    
+    Write-Host "SUCCESS - Sanitization applied!" -ForegroundColor Green
+    Write-Host ""
+    Write-Host "Check Discord - mentions should be neutralized:" -ForegroundColor Cyan
+    Write-Host "  @everyone -> @<zero-width>everyone" -ForegroundColor Gray
+    Write-Host "  @here -> @<zero-width>here" -ForegroundColor Gray
+    Write-Host "  <@123456789> -> @user" -ForegroundColor Gray
+    Write-Host "  <@&987654321> -> @role" -ForegroundColor Gray
+    Write-Host "  <#555555555> -> #channel" -ForegroundColor Gray
+    
+} catch {
+    Write-Host "FAILED!" -ForegroundColor Red
+    Write-Host $_.Exception.Message -ForegroundColor Red
+}
+
+Write-Host ""