[codex] Clean up POD email and report work

[Ngonie69]

Summary

• Allows authenticated mobile sales-order compatibility posts without an idempotency header while keeping downstream duplicate validation in place.
• Adds scheduled POD report email delivery support, SMTP diagnostics/configuration, and deployment helpers.
• Improves the order fulfillment report with order-level expansion, item-line detail, unit price, invoiced value, and richer export columns.
• Removes a couple of stale Kefalos Workshop wording references in comments.

Validation

• dotnet build ShopInventory.Web/ShopInventory.Web.csproj --no-restore
• dotnet build ShopInventory/ShopInventory.csproj --no-restore

Both builds passed with 0 warnings and 0 errors.