v0.12.0 — Inertia + domain routing

Full AdonisJS-style routing parity, plus a real Inertia adapter.

• Inertia.js server adapter — inertia("Page", props) and router.on(path).renderInertia(...). Full HTML on first load, JSON page object on XHR nav, asset-version 409s, partial reloads. (docs/inertia.md)
• Domain / subdomain routing — .domain(":tenant.example.com") on routes/groups, dispatched by Host; request.subdomain(name).
• Matchers & global constraints — router.matchers.number()/uuid()/slug()/alpha(), global router.where(), group .where().
• Brisk helpers — on().renderInertia(), .redirectToPath(), .redirectToRoute(name, params, { qs }).
• Current route — request.route, request.routeIs(name). .use() middleware alias.

45 tests, ~99% line coverage.