⚡ Bolt: [Performance] Run email sending concurrently

[Snigdh41]

💡 What: Batch resend.emails.send calls using Promise.all in the contact API.
🎯 Why: Independent HTTP requests executed sequentially block the execution unnecessarily. Running them concurrently avoids accumulated latency.
📊 Impact: Reduces overall contact API response time by the duration of the shorter network request.
🔬 Measurement: Verify worker logs/response time on successful form submission. Run workers/contact-api tests.

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PR created automatically by Jules for task 7817069411675575852 started by @Snigdh41

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