refactor(server): improve publicDir normalization

[chenjiahan]

Summary

• Remove redundant publicDir normalization calls
• Move publicDir normalization to config normalization phase
• Update NormalizedServerConfig type definitions to reflect required publicDir field

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

[netlify]

✅ Deploy Preview for rsbuild ready!

Name	Link
🔨 Latest commit	085c514
🔍 Latest deploy log	https://app.netlify.com/projects/rsbuild/deploys/68ef071693b9a30008d45f40
😎 Deploy Preview	https://deploy-preview-6360--rsbuild.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.
Lighthouse	1 paths audited Performance: 69 (no change from production) Accessibility: 97 (no change from production) Best Practices: 100 (no change from production) SEO: 100 (no change from production) PWA: 60 (no change from production) View the detailed breakdown and full score reports

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[Copilot]

Pull Request Overview

This PR refactors the server configuration to centralize publicDir normalization during the config normalization phase, eliminating redundant calls throughout the codebase. The changes improve code maintainability by ensuring publicDir is normalized once and available as a required field in NormalizedServerConfig.

• Move publicDir normalization to the config normalization phase
• Update type definitions to reflect normalized publicDir as a required field
• Remove redundant normalization calls from server files

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
packages/core/src/types/config.ts	Update NormalizedServerConfig to include required normalized publicDir field
packages/core/src/defaultConfig.ts	Move publicDir normalization to config structure phase and make function private
packages/core/src/server/watchFiles.ts	Remove redundant normalization and use normalized publicDir directly
packages/core/src/server/devMiddlewares.ts	Remove redundant normalization and use normalized publicDir directly
packages/core/src/plugins/server.ts	Remove redundant normalization and use normalized publicDir directly

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}