v0.2.1: no-clone onboarding

Use without cloning: uvx installs the tool plus example and chaos cards.

uvx --from "shadowbox @ git+https://github.com/Pa004/shadowBox.git@v0.2.1" shadowbox init --out demo
shadowbox validate model.yaml --scenario scenarios/db-failure.yaml
shadowbox simulate model.yaml --scenario cards/db-down.yaml --seed 42

New: init command (example plus 7 cards scaffold, E_EXISTS guard), wheel-bundled data via importlib.resources, canonical data moved into src/shadowbox/data with history-preserving renames, serve version from package metadata. Verified end-to-end from an isolated install: 5000/6000 ok, p99 34ms.

Fixes along the way: hatchling excludes git-ignored model.yaml (force-include), Typer single-command flattening, Rich help width in CI, vite pair alignment.