[BE-17] Add Booking Confirmation MJML email template and renderer

[devwums]

Problem

No HTML email template exists for booking confirmations. Users receive plain-text emails with no branding, making them look untrustworthy and prone to landing in spam.

Proposed Solution

Create backend/cntr/booking-confirmation.template.mjml (the MJML source) and backend/cntr/booking-confirmation.util.ts (a function renderBookingConfirmationEmail(vars): string that compiles the template using the installed mjml package). Variables: memberName, workspaceName, startDate, endDate, totalAmountNaira, bookingReference. All implementation must live inside backend/cntr/.

Acceptance Criteria

• MJML template at backend/cntr/booking-confirmation.template.mjml
• Utility at backend/cntr/booking-confirmation.util.ts
• Uses the mjml package (already in package.json)
• Compiled HTML includes all 6 variables
• Template uses ManageHub brand colour #0ea5e9 in the header
• Unit test at backend/cntr/booking-confirmation.util.spec.ts verifying the function returns HTML containing each variable value

[Danielobito009]

@Danielobito009 has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

i would love to work on this, kindly assign me to it

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[khanavi272-spec]

@khanavi272-spec has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

I would like to work on this issue

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[NteinPrecious]

@NteinPrecious has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Dear maintainers,

I would like to express my interest in working on this issue.

After reviewing the requirements, I am confident I can implement a clean and reliable solution that aligns with the project’s existing architecture and conventions. I will ensure the changes are well-structured, properly tested, and maintainable.

Please let me know if I may be assigned to this task. I would be glad to contribute.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @NteinPrecious to this issue.

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Congratulations, @NteinPrecious! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

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This issue has been completed by @NteinPrecious as part of the Stellar Wave Program's 5th Wave 🥳

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