revert: remove gh-pages branch deploy and PR preview workflow (#18)

Going with Netlify for PR previews instead, which requires zero
workflow changes and keeps the production GitHub Pages setup untouched.

Reverts deploy-pages.yml to the original GitHub Pages API approach
and removes pr-preview.yml. Also reverts the VITE_BASE_URL change
in vite.config.ts since it's no longer needed.

Co-authored-by: Hermes Alby <hermes-alby@users.noreply.github.com>

Author: hermes-alby

.github/workflows/deploy-pages.yml

@@ -6,14 +6,16 @@ on:
   workflow_dispatch:
 
 permissions:
-  contents: write
+  contents: read
+  pages: write
+  id-token: write
 
 concurrency:
   group: "pages"
   cancel-in-progress: true
 
 jobs:
-  build-deploy:
+  build:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
@@ -31,14 +33,18 @@ jobs:
       - name: Build
         run: npm run build
 
-      - name: Deploy to GitHub Pages
-        uses: peaceiris/actions-gh-pages@v4
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
         with:
-          github_token: ${{ secrets.GITHUB_TOKEN }}
-          publish_branch: gh-pages
-          publish_dir: ./dist
-          # Preserve PR preview directories so they aren't wiped on main deploy
-          keep_dirs: pr-preview
-          user_name: "github-actions[bot]"
-          user_email: "github-actions[bot]@users.noreply.github.com"
-          commit_message: "deploy: ${{ github.sha }}"
+          path: ./dist
+
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

.github/workflows/pr-preview.yml

@@ -3,7 +3,7 @@ import react from "@vitejs/plugin-react";
 import path from "node:path";
 
 export default defineConfig({
-  base: process.env.VITE_BASE_URL || "./",
+  base: "./",
   plugins: [react()],
   resolve: {
     alias: {