Modular Interlocking Dog Pen Design

I'm looking for a custom-designed, freestanding dog pen made from interlocking panels. The pen should be modular, allowing for easy deconstruction when needed.

Key Requirements:
- Interlocking Panels: Must form a secure square pen.
- Doggie Door: One panel should have a secure doggie door. Can slide up and down by human but not doggy overlord.
- Stability: Panels must be heavy enough to prevent tipping or being pushed by a Chihuahua inside.
- Smooth Interiors: Aside from interlocking areas, the inside should be as smooth as possible for dog safety and easy cleaning.
- Indoor Use: Designed for apartment living, without a bottom or top.
- Color: White to easily spot dirt.
- Photos are for general idea and size.
- Not porus. Definitely do not want material absorbing dog pee.
- Ideally pieces that slide into place with no (or as little as possible) hardware if possible.

Ideal Skills and Experience:
- Experience in custom furniture or pet product design.
- Proficiency in working with preferred materials (epoxy).
- Strong attention to detail, ensuring safety and functionality.

Please provide examples of previous work and a clear plan for construction.

Also I work nights so someone who is patient with a wonky schedule would be greatly appreciated.