chore: pre-commit hook + langchain_core import 가드 + README anchor 호환성

## pre-commit hook (.pre-commit-config.yaml)
- ruff check --fix + ruff format hooks (CI lint job mirror)
- pre-commit을 dev 의존성에 추가, CONTRIBUTING/README에 설치 안내
- 누적 lint fail이 5개 commit 이어진 사고를 구조적으로 차단

## langchain_core importorskip 가드
- tests/test_gateway_{e2e,token_saving,xgen_workflow}.py
- langchain_core 미설치 환경에서 collection error → skip 으로 전환
- 로컬 개발 마찰 제거 (CI는 --all-extras로 영향 없음)

## README anchor 호환성
- 외부 링크에서 자주 사용될 3개 헤딩 복원:
  Install → Installation, Docs → Documentation, Advanced → Advanced Features
- README.md, README-ko.md 양쪽 동기화

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: SonAIengine

.pre-commit-config.yaml

@@ -0,0 +1,21 @@
+# Pre-commit hooks for graph-tool-call
+#
+# Install once per clone:
+#     pip install pre-commit
+#     pre-commit install
+#
+# Run manually on all files:
+#     pre-commit run --all-files
+#
+# These hooks mirror the CI lint job (.github/workflows/ci.yml).
+# If they fail locally, CI will also fail — fix before committing.
+
+repos:
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.15.4
+    hooks:
+      - id: ruff
+        name: ruff check
+        args: [--fix]
+      - id: ruff-format
+        name: ruff format

CONTRIBUTING.md

@@ -7,8 +7,19 @@ Contributions are welcome! Here's how to get started.
 ```bash
 git clone https://github.com/SonAIengine/graph-tool-call.git
 cd graph-tool-call
-pip install poetry
+pip install poetry pre-commit
 poetry install --with dev --all-extras
+pre-commit install   # auto-runs ruff on every commit
+```
+
+The `pre-commit install` step wires up `.pre-commit-config.yaml` so that
+`ruff check --fix` and `ruff format` run automatically before each commit.
+This catches the same lint issues CI checks, before they reach the remote.
+
+To run the hooks manually on the whole tree:
+
+```bash
+pre-commit run --all-files
 ```
 
 ## Running Tests

README-ko.md

@@ -39,12 +39,12 @@
 
 - [왜 필요한가](#왜-필요한가)
 - [동작 원리](#동작-원리)
-- [설치](#설치)
+- [Installation](#installation)
 - [Quick Start](#quick-start)
 - [통합 패턴 고르기](#통합-패턴-고르기)
 - [벤치마크](#벤치마크)
-- [Advanced](#advanced)
-- [문서](#문서)
+- [Advanced Features](#advanced-features)
+- [Documentation](#documentation)
 - [Contributing](#contributing)
 
 </details>
@@ -105,7 +105,7 @@ graph-tool-call은 tool 하나가 아니라 체인 전체를 반환한다. 검
 
 ---
 
-## 설치
+## Installation
 
 코어 패키지는 **의존성 0** — Python 표준 라이브러리만 사용. 필요한 것만 골라 설치하면 된다.
 
@@ -303,7 +303,7 @@ python -m benchmarks.run_benchmark --mode pipeline -m qwen3:4b    # 전체 파
 
 ---
 
-## Advanced
+## Advanced Features
 
 ### Embedding 기반 hybrid search
 
@@ -368,7 +368,7 @@ tg.auto_organize(llm=openai.OpenAI())
 
 ---
 
-## 문서
+## Documentation
 
 | 문서 | 설명 |
 |---|---|
@@ -390,8 +390,9 @@ tg.auto_organize(llm=openai.OpenAI())
 ```bash
 git clone https://github.com/SonAIengine/graph-tool-call.git
 cd graph-tool-call
-pip install poetry
+pip install poetry pre-commit
 poetry install --with dev --all-extras
+pre-commit install   # 매 commit 전 ruff 자동 실행
 
 # Test, lint, benchmark
 poetry run pytest -v

README.md

@@ -39,12 +39,12 @@ English · [한국어](README-ko.md) · [中文](README-zh_CN.md) · [日本語]
 
 - [Why](#why)
 - [How it works](#how-it-works)
-- [Install](#install)
+- [Installation](#installation)
 - [Quick Start](#quick-start)
 - [Choose your integration](#choose-your-integration)
 - [Benchmark](#benchmark)
-- [Advanced](#advanced)
-- [Docs](#docs)
+- [Advanced Features](#advanced-features)
+- [Documentation](#documentation)
 - [Contributing](#contributing)
 
 </details>
@@ -105,7 +105,7 @@ graph-tool-call returns the entire chain, not just one tool. Retrieval combines
 
 ---
 
-## Install
+## Installation
 
 The core package has **zero dependencies** — just Python standard library. Install only what you need:
 
@@ -303,7 +303,7 @@ python -m benchmarks.run_benchmark --mode pipeline -m qwen3:4b    # full pipelin
 
 ---
 
-## Advanced
+## Advanced Features
 
 ### Embedding-based hybrid search
 
@@ -368,7 +368,7 @@ Builds richer categories, relations, and search keywords. Supports Ollama, OpenA
 
 ---
 
-## Docs
+## Documentation
 
 | Doc | Description |
 |---|---|
@@ -390,8 +390,9 @@ Contributions are welcome.
 ```bash
 git clone https://github.com/SonAIengine/graph-tool-call.git
 cd graph-tool-call
-pip install poetry
+pip install poetry pre-commit
 poetry install --with dev --all-extras
+pre-commit install   # auto-runs ruff on every commit
 
 # Test, lint, benchmark
 poetry run pytest -v

poetry.lock

@@ -70,6 +70,7 @@ all = ["networkx", "pyyaml", "numpy", "sentence-transformers", "rapidfuzz", "lan
 pytest = "^8.0"
 pytest-asyncio = "^0.23"
 ruff = ">=0.11"
+pre-commit = "^4.0"
 langgraph-bigtool = "^0.0.3"
 
 [tool.ruff]

pyproject.toml

@@ -8,10 +8,11 @@
 import json
 import time
 
-from langchain_core.tools import tool
-
 pytest = __import__("pytest")
+pytest.importorskip("langchain_core")
+pytest.importorskip("langgraph")
 ChatOllama = pytest.importorskip("langchain_ollama").ChatOllama
+from langchain_core.tools import tool  # noqa: E402
 from langgraph.prebuilt import create_react_agent  # noqa: E402
 
 from graph_tool_call.langchain.gateway import create_gateway_tools  # noqa: E402

tests/test_gateway_e2e.py

@@ -9,10 +9,10 @@
 
 import json
 
-from langchain_core.tools import tool
-
 pytest = __import__("pytest")
+pytest.importorskip("langchain_core")
 ChatOllama = pytest.importorskip("langchain_ollama").ChatOllama
+from langchain_core.tools import tool  # noqa: E402
 
 from graph_tool_call.langchain.gateway import create_gateway_tools  # noqa: E402