[CI] add format hook

.pre-commit-config.yaml

@@ -23,6 +23,16 @@ repos:
       - id: check-added-large-files
         args: ['--maxkb=1024']
 
+  - repo: local
+    hooks:
+      - id: mooncake-code-format
+        name: Run Mooncake code format script
+        entry: ./scripts/code_format.sh
+        language: system
+        pass_filenames: false
+        always_run: true
+        require_serial: true
+
   - repo: https://github.com/astral-sh/ruff-pre-commit
     rev: v0.6.9
     hooks:

CONTRIBUTING.md

@@ -41,6 +41,7 @@ Mooncake uses [pre-commit](https://pre-commit.com/) to enforce consistent format
 | Type | Tool | Purpose |
 |------|------|---------|
 | Generic | trailing-whitespace / end-of-file-fixer | Basic hygiene |
+| Project | `./scripts/code_format.sh` | Enforce Mooncake C/C++ formatting script before commit |
 | Python | ruff / ruff-format | Lint + format (includes import sorting) |
 | Spelling | codespell | Catch common typos (ignores domain-specific words) |
 | C/C++ | clang-format | Apply style from the repository's `.clang-format` |
@@ -53,6 +54,8 @@ pip install -r requirements-dev.txt
 pre-commit install
 ```
 
+After installation, every commit will run `./scripts/code_format.sh` automatically. If it rewrites files, re-stage the changes and commit again.
+
 #### Usage
 Run on all files (first run will install hook environments):
 ```bash