chore(CI): adapt GitHub action to Nix environment

.github/workflows/ci.yml

@@ -4,31 +4,37 @@ on: push
 
 jobs:
   ci:
-    runs-on: ${{ matrix.os }}
-
-    strategy:
-      matrix:
-        os: [ubuntu-latest]
-        node: [22]
+    runs-on: ubuntu-latest
 
     steps:
       - name: Checkout
         uses: actions/checkout@v6
 
-      - name: Install pnpm
-        uses: pnpm/action-setup@v4
-
-      - name: Install node
-        uses: actions/setup-node@v6
+      - name: Install Nix
+        uses: cachix/install-nix-action@v27
         with:
-          node-version: ${{ matrix.node }}
-          cache: pnpm
+          nix_path: nixpkgs=channel:nixos-unstable
 
       - name: Install dependencies
-        run: pnpm install
-
-      - name: Lint
-        run: pnpm run lint
+        run: |
+            nix develop --no-pure-eval --command pnpm install --frozen-lockfile
 
       - name: Typecheck
-        run: pnpm run typecheck
+        run: |
+            nix develop --no-pure-eval --command pnpm run typecheck
+
+      - name: Lint
+        run: |
+            nix develop --no-pure-eval --command pnpm run lint
+
+      - name: Check formatting
+        run: |
+            nix develop --no-pure-eval --command pnpm run format-check
+
+      - name: Tests
+        run: |
+            nix develop --no-pure-eval --command pnpm run test
+
+      - name: Build
+        run: |
+            nix develop --no-pure-eval --command pnpm run build