Use import() syntax in route manifest for IDE navigation

[JoviDeCroock]

Summary

• Route manifests now accept () => import("./path") as the module reference, enabling ctrl+click navigation in IDEs (VS Code, JetBrains, etc.)
• The vite plugin transforms these back to plain strings at build time via a regex-based transform hook, so internal string-based resolution is unchanged
• Added ModuleRef type (string | (() => Promise<any>)) to route(), defineApp shells/middleware, and RouteConfig
• Pages router generated manifests now emit () => import() syntax
• Plain string paths remain fully supported (backwards compatible)

Test plan

• pnpm build passes
• pnpm typecheck — same pre-existing failures as main (missing external type declarations)
• pnpm test — same pre-existing failures as main (missing preact-suspense)
• pnpm e2e — same pre-existing failures as main (pnpm workspace linking issue locally)
• CI should pass — all failures are identical to main branch

🤖 Generated with Claude Code