Add one-command setup script for Linux laptops

Usage: git clone <repo> && cd innovatieplatform && bash setup.sh

The script:
- Checks for docker and docker compose v2
- Creates .env from .env.example with auto-generated APP_KEY
- Builds all 7 Docker containers
- Waits for PostgreSQL and Redis health checks
- Runs migrations and seeds with 2026 planning + student data
- Builds frontend (if npm available locally)
- Prints access URLs and credentials

Prerequisites: docker, docker compose. That's it.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.env.example

@@ -1,4 +1,4 @@
-APP_NAME=Laravel
+APP_NAME=Innovatieplatform
 APP_ENV=local
 APP_KEY=
 APP_DEBUG=true