Add justfile for dev tasks

justfile

@@ -0,0 +1,28 @@
+# Default: run all checks, fixes, and tests
+default: fix check test
+
+# Run all linting and type checks
+check:
+    uv run ruff check .
+    uv run mypy tensors/
+
+# Run tests
+test:
+    uv run pytest
+
+# Auto-fix linting issues and format code
+fix:
+    uv run ruff check --fix .
+    uv run ruff format .
+
+# Format code only
+format:
+    uv run ruff format .
+
+# Lint only (no fixes)
+lint:
+    uv run ruff check .
+
+# Type check only
+types:
+    uv run mypy tensors/