ci: add pre-commit hooks for code quality

.pre-commit-config.yaml

@@ -1,16 +1,48 @@
-# Pre-commit hooks for secret scanning
+# Pre-commit hooks for DreamServer
 # Install: pip install pre-commit && pre-commit install
 # Run manually: pre-commit run --all-files
 
 repos:
+  # Secret scanning
   - repo: https://github.com/gitleaks/gitleaks
     rev: v8.21.2
     hooks:
       - id: gitleaks
 
+  # Shell script linting
+  - repo: https://github.com/shellcheck-py/shellcheck-py
+    rev: v0.10.0.1
+    hooks:
+      - id: shellcheck
+        args: ["--exclude=SC1091,SC2034,SC2086", "--severity=error"]
+        files: \.sh$
+
+  # Python linting with Ruff
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.3.4
+    hooks:
+      - id: ruff
+        args: ["--select", "E,F,W", "--ignore", "E501"]
+        files: ^dream-server/.*\.py$
+
+  # Python formatting with Black
+  - repo: https://github.com/psf/black
+    rev: 24.3.0
+    hooks:
+      - id: black
+        args: ["--line-length=100"]
+        files: ^dream-server/.*\.py$
+
+  # General file checks
   - repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v5.0.0
     hooks:
       - id: detect-private-key
       - id: check-added-large-files
         args: ['--maxkb=500']
+      - id: trailing-whitespace
+        exclude: \.md$
+      - id: end-of-file-fixer
+      - id: check-yaml
+        args: ["--unsafe"]
+      - id: check-json

CONTRIBUTING.md

@@ -34,6 +34,36 @@ Nothing exotic:
 - **Python** uses standard formatting (we're not picky -- just be consistent with the file you're editing).
 - Keep things readable. Comments are welcome where intent isn't obvious.
 
+## Pre-commit Hooks
+
+This project uses pre-commit hooks to ensure code quality. To set up:
+
+```bash
+pip install pre-commit
+pre-commit install
+```
+
+The hooks will run automatically on `git commit` and check for:
+- Secret leaks (gitleaks)
+- Shell script issues (shellcheck)
+- Python linting (ruff)
+- Python formatting (black)
+- Large files, trailing whitespace, YAML/JSON syntax
+
+To run hooks manually on all files:
+
+```bash
+pre-commit run --all-files
+```
+
+To bypass hooks (not recommended):
+
+```bash
+git commit --no-verify
+```
+
+**Note:** All Python files have been formatted with `black --line-length=100`. The pre-commit hooks will enforce this formatting going forward.
+
 ## Pull Request Process
 
 1. **Describe your changes** in the PR description. A sentence or two is fine for small changes; more detail helps for larger ones.