added linting tool defiition and linting yaml

.github/workflows/python-lint.yml

@@ -0,0 +1,31 @@
+name: Python Lint
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+          cache: 'pip'
+
+      - name: Install tooling
+        run: pip install black ruff bandit
+
+      - name: Black — code format check
+        run: black --check .
+
+      - name: Ruff — style & bug lint
+        run: ruff check .
+
+      - name: Bandit — security scan
+        run: bandit -r .
+
+

pyproject.toml

@@ -0,0 +1,10 @@
+[tool.black]
+line-length = 100
+
+[tool.ruff]
+select = ["E", "F", "B"]      # style & bug rules
+line-length = 100
+ignore = ["E501"]             # long lines handled by Black
+
+[tool.bandit]
+skips = ["B101"]              # adjust to taste