feat: support ingress subpaths

[sancfc]

Summary

Adds support for serving Penpot from a configurable subpath while preserving the default root-path behavior.

Changes

• Adds configurable ingress.pathType, defaulting to Prefix.
• Documents how to deploy Penpot under a subpath with NGINX Ingress.
• Adds a valid values fixture for /penpot/.
• Updates the values schema and generated README.
• Ensures the local ingress controller runs on the Kind node exposing ports 80 and 443.

Validation

Tested both configurations in a clean Kind cluster:

• Penpot served from /.
• Penpot served from /penpot/.
• Upgrade from / to /penpot/ preserving users, projects, files and uploaded assets.
• HTML, JavaScript and CSS resources returned successfully in both modes.

[bameda]

I’m trying it with ingress and the admin console enabled and it’s throwing an error.