feat: add proration invoice and reminder email templates

[sean-brydon]

Summary

• Add email templates for monthly proration billing notifications
• ProrationInvoiceEmail: Sent when invoice is created for additional seats
• ProrationReminderEmail: Sent 7 days later if invoice remains unpaid

Changes

• React email templates using V2BaseEmailHtml
• BaseEmail classes for rendering
• Billing email service functions (sendProrationInvoiceEmails, sendProrationReminderEmails)
• Translation keys for email content

Test plan

• Verify email templates render correctly
• Verify translation keys are correct
• Type check passes

[sean-brydon]

Formatting

[eunjae-lee]

Promise.allSettled() ?

[cubic-dev-ai]

1 issue found across 7 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="packages/emails/templates/proration-reminder-email.ts">

<violation number="1" location="packages/emails/templates/proration-reminder-email.ts:68">
P2: Use the existing translation keys for the plain-text body instead of embedding the English string directly so the reminder email localizes correctly.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

P2: Use the existing translation keys for the plain-text body instead of embedding the English string directly so the reminder email localizes correctly.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At packages/emails/templates/proration-reminder-email.ts, line 68:

<comment>Use the existing translation keys for the plain-text body instead of embedding the English string directly so the reminder email localizes correctly.</comment>

<file context>
@@ -0,0 +1,70 @@
+
+  protected getTextBody(): string {
+    const formattedAmount = (this.proration.proratedAmount / 100).toFixed(2);
+    return `Reminder: Your invoice of $${formattedAmount} for team ${this.team.name} is still unpaid. Please pay to avoid restrictions on adding new users.`;
+  }
+}
</file context>

[github-actions]

Devin AI is addressing Cubic AI's review feedback

A Devin session has been created to address the issues identified by Cubic AI.

View Devin Session

[devin-ai-integration]

I reviewed the Cubic AI feedback for this PR. The issue identified at packages/emails/templates/proration-reminder-email.ts:68 regarding using translation keys for the plain-text body has a confidence score of 8/10.

Per my instructions, I'm only addressing issues with a confidence score of 9/10 or higher. Since this issue is below that threshold, I'm skipping it for now. The PR author or reviewers can decide whether to address this feedback manually.