🔧 Optimize API rate limit configuration

[coderabbitai]

Description

The current API rate limit is set to 2 requests per second per authorization header in the AWS WAF configuration. This might be too restrictive for typical API usage patterns and could impact user experience.

Task

Review and potentially increase the rate limit to a more suitable value for production usage.

Context

• Current setting: 2 RPS per authorization header
• Location: infra/api.ts line 56
• Discussion originated from PR review feedback

References

• PR: ⭐ feat(infra): Migrate to serverless Lambda architecture #291
• Comment: ⭐ feat(infra): Migrate to serverless Lambda architecture #291 (comment)

Requested by: @wanjohiryan