fix(ci): quote PR title fields in update workflow

.github/workflows/check-nixos.yml

@@ -0,0 +1,27 @@
+name: Check NixOS configurations
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+  eval-hosts:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Install Nix
+        uses: DeterminateSystems/nix-installer-action@v19
+
+      - name: Evaluate all NixOS hosts
+        run: |
+          set -euo pipefail
+          for host in nixos docker kuma server nix-cache nix-minimal; do
+            echo "Evaluating ${host}"
+            nix --extra-experimental-features 'nix-command flakes' eval \
+              ".#nixosConfigurations.${host}.config.system.build.toplevel.drvPath" --raw
+          done

.github/workflows/update-flake-lock.yml

@@ -0,0 +1,37 @@
+name: Update flake.lock
+
+on:
+  schedule:
+    - cron: "0 6 * * 1"
+  workflow_dispatch:
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  update-flake-lock:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Install Nix
+        uses: DeterminateSystems/nix-installer-action@v19
+
+      - name: Update flake.lock
+        run: |
+          nix --extra-experimental-features 'nix-command flakes' flake update
+
+      - name: Create pull request
+        uses: peter-evans/create-pull-request@v6
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          add-paths: flake.lock
+          branch: chore/update-flake-lock
+          title: "chore: update flake.lock"
+          commit-message: "chore: update flake.lock"
+          body: |
+            This is an automated update of `flake.lock` generated by the scheduled workflow.
+            
+            It updates pinned flake inputs so dependency updates can be reviewed and merged via PR.