fix: use static params in file-system based router for ssg

[lazarv]

Implements static parameters support in the file-system based router and validates input parameters for static routes at static-site generation phase of an application build. Converts static parameters defined in a .static.{ts,mjs,json} to SSG compatible format.

Static parameters exported as default:

// /posts/[id].static.ts
export default [{ id: 1 }, { id: 2 }, { id: 3 }]

Converted to the default format used in exports of configuration in a react-server.config.mjs:

[{ path: "/posts/1" }, { path: "/posts/2" }, { path: "/posts/3" }]

#81