SIENTIAPDE-1231

Enhance README with code quality and validation guidelines

- Added a new section on code quality and validation tools, detailing the use of Ruff, mypy, Bandit, and pytest.
- Included installation instructions for development dependencies and options for running validation scripts.
- Provided best practices for maintaining code quality and integrating CI/CD workflows.

README.md

@@ -511,6 +511,68 @@ fi
 python -m laborious.worker.worker
 ```
 
+## Code Quality & Validation
+
+### Overview
+
+Since Python is not compiled, we validate quality, security, and correctness before execution.
+
+### Validation Tools
+
+- Ruff: Linting and formatting
+- mypy: Static type checking
+- Bandit: Security analysis
+- pytest: Unit/integration testing with coverage
+
+### Tools Installation
+
+```bash
+pip install -r requirements-dev.txt
+```
+
+### Complete Validation
+
+Option 1 (recommended):
+```bash
+./validate.sh
+```
+The script runs, in order:
+1. Format check (Ruff)
+2. Linting (Ruff)
+3. Type checking (mypy)
+4. Security analysis (Bandit)
+5. Tests with coverage (pytest)
+
+Option 2 (individual commands):
+```bash
+ruff format --check laborious/ tests/
+ruff check laborious/ tests/
+mypy laborious/
+bandit -r laborious/ -ll
+pytest tests/ --cov=laborious --cov-report=term-missing
+```
+
+### Automatic Fixes
+
+```bash
+ruff format laborious/ tests/
+ruff check --fix laborious/ tests/
+```
+
+### Configuration
+
+All settings reside in `pyproject.toml` (Ruff, mypy, pytest, Bandit).
+
+### CI/CD Integration
+
+The workflow at `.github/workflows/quality-gate.yml` executes validations on each push/PR.
+
+### Best Practices
+
+- Run `./validate.sh` before committing
+- Use `ruff check --watch` for continuous feedback
+- Add type hints and tests for new code
+
 ## 🧪 Testing
 
 ### Test Structure