fix: migrate Lambda to Graviton - $47,462/yr savings

[infracost]

💰 Infracost opened this pull request as part of the following campaign:

Manual Optimization Campaign

Policy: Lambda - consider using Graviton Graviton lambda functions are 20% cheaper than x86 equivalents with up to 19% improved performance. If you do not use x86 binary dependencies, setting lambda functions to use ARM64 can result in significant savings and improved performance. See [AWS docs](https://aws.amazon.com/blogs/aws/aws-lambda-functions-powered-by-aws-graviton2-processor-run-your-functions-on-arm-and-get-up-to-34-better-price-performance/) for details.	Potential savings: $47,462/yr
Risk: Medium migrating functions to ARM64 architecture may introduce compatibility issues with native libraries and subtle behavior differences.
Deployment details: May require downtime, Please see AWS docs for details Changing the runtime architecture of a Lambda function can cause a brief service disruption if you are using a custom runtime. You can minimize this by implementing canary or blue-green deployments. AWS Blog

Next steps:
✅ Deploy this change before the campaign deadline: April 7, 2026
💬 False positive? Add a PR comment with @infracost dismiss
🛠️ Incorrect code fix? Close the PR with a comment or check out the branch to adjust

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