[Feature]: Move production API access toward direct HTTPS or custom-domain support

[nikkogibler]

Area

API or backend

What problem are you trying to solve?

The current production frontend relies on Vercel proxying /api/* requests to a raw VPS HTTP API endpoint. That works, but it is not the cleanest long-term production setup.

Proposed solution

Move production API access toward a more direct HTTPS or custom-domain setup while preserving browser compatibility and clear deployment docs.

Acceptance criteria:

• propose and implement a production-ready HTTPS or domain-based API access path
• update repo docs to match the new setup
• verify browser requests continue to work without mixed-content problems

Alternatives considered

• Keep the current Vercel proxy setup indefinitely. This works for now, but it leaves the API architecture less direct and less production-clean than it could be.
• Rework the whole deployment stack at once. That may be worthwhile later, but it is broader than needed for solving the API HTTPS/domain-path problem.

Scope and impact

• move toward a cleaner production networking model
• reduce dependence on a raw HTTP VPS endpoint behind Vercel proxying
• support a direct HTTPS API path or a custom domain in front of the API

Relevant files:

• vercel.json
• documentation/deployment.md
• README.md
• VPS Docker deployment flow documented in the repo

Notes:

This is not a beginner issue. It touches production deployment, routing, and environment configuration.

Pre-flight checks

• I searched existing issues and did not find a duplicate.
• I explained the problem, not just the desired feature.