[BUG] images route does not support public folder from theme

[treoden]

Describe the bug
The images route does not support serving assets from the public folder within the current theme. This prevents theme-specific images from loading via the expected route, likely causing missing image errors in storefronts that rely on custom themes.

To Reproduce
Steps to reproduce the behavior:

1. Use a theme that places images in its public folder (e.g. /themes/your-theme/public/images).
2. Attempt to reference these images via the /images route.
3. The images are not served as expected and result in 404 or missing assets.

Expected behavior
The /images route should serve images from the public folder of the active theme. This allows theme developers to provide custom assets per theme.

Screenshots

Background (please complete the following information):

• NodeJS Version
• Postgres Version
• EverShop Version
• OS: [e.g. Window, Ubuntu, Mac-OS]
• Browser [e.g. Chrome, Safari]

Additional context
Allowing /images to support the theme public folder improves theme customization and asset organization.