Bootstrap monorepo: Hono API, React PWA, Drizzle DB, CI/CD

Sets up the initial project structure for groombook/groombook:

- pnpm monorepo with apps/api (Hono + TypeScript), apps/web (React + Vite + PWA), packages/db (Drizzle ORM), packages/types (shared types)
- Core DB schema: clients, pets, services, appointments, staff with CNPG-compatible Postgres
- REST API routes for clients, pets, services, appointments with Zod validation
- OIDC auth middleware for Authentik integration
- React PWA with vite-plugin-pwa, service worker, offline caching, installable manifest
- GitHub Actions CI: lint, typecheck, test, build, Docker image build (groombook-runners)
- Dockerfiles for API (Node.js) and Web (nginx)
- docker-compose.yml for local development

Co-Authored-By: Paperclip <noreply@paperclip.ing>

.editorconfig

@@ -0,0 +1,12 @@
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+trim_trailing_whitespace = false