Deploy geo-distributed try.coder.app services for better global performance

## Problem
Users outside the transatlantic region find try.coder.app unbearably slow, which negatively affects their first impressions of our product. This is particularly impactful when sharing Coder with APAC/EMEA communities where the try URLs are currently unusable.

## Solution
Deploy multiple geo-distributed instances of try.coder.app to improve performance for users worldwide.

## Implementation Options
- **Fly.io**: Has global footprint with logic to connect users to closest region and auto-sleep capabilities
- Other cloud providers with multi-region support

## Effort Estimate
~Few days of development work

## Context
Currently deployed on Teraswitch VPS. Moving to a multi-region setup would significantly improve user experience globally.