feat: add justfile for development commands (#99)

- Adds a justfile with common development commands for easier workflow
- Commands: `install`, `test`, `test-unit`, `test-browser`, `lint`, `web`, `kill-web`, `doc`, `kill-doc`, `clean`

CLAUDE.md

@@ -58,9 +58,24 @@ Icons use [Lucide](https://lucide.dev/). Add new icons as macros in `web/templat
 
 - **Imports at top level**: Never add imports inside functions unless they are explicitly marked with `# noqa: PLC0415` and a comment explaining it speeds up CLI startup. Heavy modules like `pydantic`, `yaml`, and `rich.table` are lazily imported to keep `cf --help` fast.
 
+## Development Commands
+
+Use `just` for common tasks. Run `just` to list available commands:
+
+| Command | Description |
+|---------|-------------|
+| `just install` | Install dev dependencies |
+| `just test` | Run all tests |
+| `just test-unit` | Run unit tests (parallel) |
+| `just test-browser` | Run browser tests |
+| `just lint` | Lint, format, and type check |
+| `just web` | Start web UI (port 9001) |
+| `just doc` | Build and serve docs (port 9002) |
+| `just clean` | Clean build artifacts |
+
 ## Testing
 
-Run tests with `uv run pytest`. Browser tests require Chromium (system-installed or via `playwright install chromium`):
+Run tests with `just test` or `uv run pytest`. Browser tests require Chromium (system-installed or via `playwright install chromium`):
 
 ```bash
 # Unit tests only (skip browser tests, can parallelize)

justfile

@@ -0,0 +1,52 @@
+# Compose Farm Development Commands
+# Run `just` to see available commands
+
+# Default: list available commands
+default:
+    @just --list
+
+# Install development dependencies
+install:
+    uv sync --all-extras --dev
+
+# Run all tests (no coverage for speed)
+test:
+    uv run pytest --no-cov
+
+# Run unit tests only (parallel, with coverage)
+test-unit:
+    uv run pytest -m "not browser" -n auto
+
+# Run browser tests only (sequential, no coverage)
+test-browser:
+    uv run pytest -m browser --no-cov
+
+# Lint, format, and type check
+lint:
+    uv run ruff check --fix .
+    uv run ruff format .
+    uv run mypy src
+    uv run ty check src
+
+# Start web UI in development mode with auto-reload
+web:
+    uv run cf web --reload --port 9001
+
+# Kill the web server
+kill-web:
+    lsof -ti :9001 | xargs kill -9 2>/dev/null || true
+
+# Build docs and serve locally
+doc:
+    uvx zensical build
+    python -m http.server -d site 9002
+
+# Kill the docs server
+kill-doc:
+    lsof -ti :9002 | xargs kill -9 2>/dev/null || true
+
+# Clean up build artifacts and caches
+clean:
+    rm -rf .pytest_cache .mypy_cache .ruff_cache .coverage htmlcov dist build
+    find . -type d -name __pycache__ -exec rm -rf {} + 2>/dev/null || true
+    find . -type d -name "*.egg-info" -exec rm -rf {} + 2>/dev/null || true