ci: run pre-commit checks

.github/workflows/pre-commit.yml

@@ -0,0 +1,53 @@
+name: Pre-commit
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+permissions:
+  contents: read
+
+concurrency:
+  group: pre-commit-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.14"
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.24.x"
+
+      - name: Install StyLua
+        run: |
+          mkdir -p "$HOME/.local/bin"
+          curl --fail --location --silent --show-error \
+            https://github.com/JohnnyMorganz/StyLua/releases/download/v2.5.2/stylua-linux-x86_64.zip \
+            --output /tmp/stylua.zip
+          unzip -q /tmp/stylua.zip -d "$HOME/.local/bin"
+          echo "$HOME/.local/bin" >> "$GITHUB_PATH"
+
+      - name: Install shfmt
+        run: |
+          go install mvdan.cc/sh/v3/cmd/shfmt@v3.14.1
+          echo "$(go env GOPATH)/bin" >> "$GITHUB_PATH"
+
+      - uses: actions/cache@v4
+        with:
+          path: ~/.cache/pre-commit
+          key: pre-commit-${{ runner.os }}-${{ hashFiles('.pre-commit-config.yaml') }}
+
+      - name: Run pre-commit
+        # Ghostty is macOS-oriented and is intentionally validated locally; installing it on
+        # a macOS runner would make this otherwise fast backup check considerably slower.
+        run: |
+          python -m pip install --disable-pip-version-check pre-commit==4.6.2
+          SKIP=ghostty-validate-config pre-commit run --all-files