chore: add pre-commit configuration and CI

.codespellignore

@@ -0,0 +1,4 @@
+mor
+tok
+fpan
+dpan

.github/workflows/linter.yml

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+#   Copyright 2026 Google LLC
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+
+name: Lint
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  pre-commit:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-python@v5
+      with:
+        python-version: '3.x'
+    - uses: pre-commit/action@v3.0.1

.gitignore

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+node_modules/
+.ruff_cache/
+__pycache__/
+.venv/
+*.py[cod]

.pre-commit-config.yaml

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+#   Copyright 2026 Google LLC
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+
+exclude: '^(\.github/|\.vscode/|node_modules/).*|CODE_OF_CONDUCT\.md|CHANGELOG\.md'
+
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v6.0.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+        args: [--unsafe]
+      - id: check-json
+      - id: check-added-large-files
+      - id: check-shebang-scripts-are-executable
+      - id: check-executables-have-shebangs
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.14.13
+    hooks:
+      - id: ruff
+        args: [--fix, --exit-non-zero-on-fix, --ignore, "D,E501"]
+      - id: ruff-format
+  - repo: https://github.com/pre-commit/mirrors-prettier
+    rev: v4.0.0-alpha.8
+    hooks:
+      - id: prettier
+        files: \.(md|yaml|yml|json)$
+  - repo: https://github.com/koalaman/shellcheck-precommit
+    rev: v0.10.0
+    hooks:
+      - id: shellcheck
+  - repo: https://github.com/codespell-project/codespell
+    rev: v2.4.1
+    hooks:
+      - id: codespell
+        args: ["-I", ".codespellignore"]