feat: add uv-based project with pytest and CI workflow

- Add pyproject.toml and uv.lock for Python project with uv
- Add src/__init__.py with add(), multiply(), greet() functions
- Add tests/test_example.py with unit tests
- Add commit-message skill for Conventional Commits
- Add Gitea Actions workflow to run pytest

tests/test_example.py

@@ -0,0 +1,17 @@
+import pytest
+from src import add, multiply, greet
+
+
+def test_add():
+    assert add(1, 2) == 3
+    assert add(-1, 1) == 0
+
+
+def test_multiply():
+    assert multiply(2, 3) == 6
+    assert multiply(0, 5) == 0
+
+
+def test_greet():
+    assert greet("World") == "Hello, World!"
+    assert greet("") == "Hello, !"