feat: docker compose dev environment

Replaces the bare-metal `composer run dev` workflow with a fully
containerized 9-service stack orchestrated by docker compose. Single
command brings up the full app — three subdomains (marketing /
account / admin) reachable via Traefik with TLS, MariaDB + Valkey
+ Mailpit + Vite HMR + Horizon + scheduler all wired in.

Components:
- docker-compose.yml: traefik, app (php-fpm), web (nginx), mariadb,
  valkey, mailpit, vite, horizon, scheduler.
- docker/: Dockerfiles, nginx config, entrypoint scripts.
- Makefile: convenience targets (up / down / logs / shell / migrate
  / seed / test / pint / etc).
- .env.docker.example: template for Docker-stack environment vars
  (separate from website/.env so bare-metal devs aren't disrupted).
- website/vite.config.ts: server.host / origin / hmr / cors hooks
  driven by VITE_HOST / VITE_ORIGIN / VITE_HMR_HOST so the same
  config serves both bare-metal and Docker.
- website/bootstrap/app.php: redirectGuestsTo() now uses
  request()->getScheme() so http: dev hosts don't get force-https
  redirects.
- composer.json: drops laravel/sail (replaced by this stack).
- docs/superpowers/specs/2026-04-25-docker-compose-dev-environment-design.md:
  full design spec.

Bare-metal `composer run dev` workflow stays usable for anyone who
prefers it — Docker stack reads .env.docker, doesn't fight
website/.env.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docker/app/php.ini

@@ -0,0 +1,24 @@
+; ==============================================================================
+; EZSCALE dev overrides — applied AFTER php.ini-development
+; ==============================================================================
+
+memory_limit = 512M
+max_execution_time = 120
+post_max_size = 50M
+upload_max_filesize = 50M
+max_input_vars = 5000
+
+display_errors = On
+display_startup_errors = On
+error_reporting = E_ALL
+log_errors = On
+
+date.timezone = UTC
+
+; Session handling delegated to Laravel; keep PHP-side defaults sane
+session.cookie_httponly = 1
+session.cookie_samesite = "Lax"
+
+; Realpath cache helps Composer/Laravel reload cycles
+realpath_cache_size = 4096K
+realpath_cache_ttl = 600