style: Format code with Black and fix CI workflows

- Fixed GitHub Actions workflows to use requirements-dev.txt
- Formatted all Python files with Black to pass linting checks
- Updated both lint.yml and tests.yml workflows

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: biyachuev

.github/workflows/lint.yml

@@ -21,7 +21,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install flake8 black mypy
+        pip install -r requirements-dev.txt
 
     - name: Run flake8
       run: |

.github/workflows/tests.yml

@@ -34,7 +34,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install -r requirements.txt
-        pip install pytest pytest-cov python-docx
+        pip install -r requirements-dev.txt
 
     - name: Run tests
       run: |