✨ Enhancement: Improve Next.js build configuration readability and documentation

Is your feature request related to a problem? Please describe

The current Next.js configuration (next.config.js) contains custom Webpack logic,
static export settings, and image optimization overrides that work correctly but
are difficult to understand for new contributors.

Improving documentation and structure would make the build setup clearer and
reduce onboarding friction.

• Custom Webpack rules are embedded directly in next.config.js
• Limited inline documentation explaining:
  • Why output: 'export' is required
  • Why images.unoptimized is enabled
  • How environment-based conditions (dev, isServer) are intended to work

Describe the solution you'd like

• Improve readability of next.config.js
• Add comments explaining non-default Next.js and Webpack settings
• Clarify environment-specific behavior without changing functionality

Describe alternatives you've considered

Leave the configuration as-is, but this continues to make onboarding harder
and increases the risk of accidental misconfiguration.

Additional context

This change is documentation- and structure-focused only and does not propose
any functional or behavioral changes.

Are you working on this?

Yes

Start with next.config.js, focusing on the embedded Webpack logic, output: 'export', images.unoptimized, and the dev/isServer conditions. Improve the structure and add comments explaining these non-default settings without changing functionality, then verify the build configuration still behaves as before.