feat(ci): replace ci.yml with ci-deploy.yml

Replace the old ci.yml workflow with a new ci-deploy.yml workflow
that includes both testing and GitHub Pages deployment. The new
workflow runs tests first and only deploys to GitHub Pages if
the tests pass successfully. Deployment is gated to push events
on the main branch only, preventing deployments from pull requests.

Author: Atliac

.github/workflows/ci-deploy.yml

@@ -0,0 +1,74 @@
+name: CI & Deploy
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
+permissions:
+  contents: write
+  pages: write
+  id-token: write
+
+jobs:
+  # --- JOB 1: TEST ---
+  test:
+    name: Run Rust Doc Tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Install Rust
+        run: |
+          rustup set profile minimal
+          rustup toolchain install stable
+          rustup default stable
+
+      - name: Install latest mdbook
+        run: |
+          tag=$(curl 'https://api.github.com/repos/rust-lang/mdbook/releases/latest' | jq -r '.tag_name')
+          url="https://github.com/rust-lang/mdbook/releases/download/${tag}/mdbook-${tag}-x86_64-unknown-linux-gnu.tar.gz"
+          mkdir bin
+          curl -sSL $url | tar -xz --directory=bin
+          echo "$(pwd)/bin" >> $GITHUB_PATH
+
+      - name: Run tests
+        run: mdbook test
+
+  # --- JOB 2: DEPLOY ---
+  deploy:
+    name: Deploy to GitHub Pages
+    runs-on: ubuntu-latest
+    needs: test # This ensures Deploy ONLY runs if Test passes!
+    # This ensures Deploy ONLY runs on the main branch, not on PRs
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+
+      - name: Install latest mdbook
+        run: |
+          tag=$(curl 'https://api.github.com/repos/rust-lang/mdbook/releases/latest' | jq -r '.tag_name')
+          url="https://github.com/rust-lang/mdbook/releases/download/${tag}/mdbook-${tag}-x86_64-unknown-linux-gnu.tar.gz"
+          mkdir bin
+          curl -sSL $url | tar -xz --directory=bin
+          echo "$(pwd)/bin" >> $GITHUB_PATH
+
+      - name: Build Book
+        run: mdbook build
+
+      - name: Setup Pages
+        uses: actions/configure-pages@v4
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: "book" # The default mdbook output folder
+
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4