Fix notification email showing wrong order amount ($149.99 displayed as $1.50)

[devin-ai-integration]

Summary

Order confirmation notification emails were displaying incorrect amounts — a $149.99 order appeared as $1.50 in the email preview.

Root cause: NotificationRenderer.FormatCurrency() divided the TotalAmount by 100, assuming the value was transmitted in cents. However, the OrderPlacedEvent shared contract defines TotalAmount as a decimal in dollars, not cents. The division produced 149.99 / 100 = 1.4999, which rounded to $1.50.

Fix: Removed the erroneous /100m division so the dollar amount is formatted directly.

Review & Testing Checklist for Human

• Verify the TotalAmount contract: Confirm that all current and planned producers of OrderPlacedEvent send TotalAmount in dollars (not cents). The Order service is currently scaffolded, so check with the team that the intended contract is dollars. If any producer sends cents, this fix would be wrong and the contract needs to be clarified.
• Reproduce end-to-end: Run the notification service locally, POST {"orderId": "11111111-1111-1111-1111-111111111111", "customerId": "22222222-2222-2222-2222-222222222222", "totalAmount": 149.99, "placedAt": "2026-03-17T12:00:00Z"} to /api/notification/events/order-placed, then open the preview URL and confirm the total shows $149.99.
• Edge cases: Test with amounts like 0.01 (one cent), 1000.00, and 0.10 to verify formatting across different magnitudes.

Notes

• The full solution could not be built locally due to a pre-existing issue with the Shared.Contracts project reference path in the .csproj (relative path ../../Shared/... doesn't resolve when building the project standalone). This is unrelated to this change.
• No unit tests exist for FormatCurrency; consider adding them to prevent regressions.

Link to Devin session: https://partner-workshops.devinenterprise.com/sessions/4b31c83c48bb4bbe84d3dba130d00fe7

[devin-ai-integration]

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