🔥 Remove Laravel Sail, Docker, and related setup, migrate to simplified local development environment

- **Removed:** `docker-compose.yml`, Sail-specific Dockerfiles, and related scripts for PHP 8.3 setup.
- **Updated:** Documentation to reflect a shift from Docker to a direct PHP-based local development workflow.
- **Removed:** `laravel/sail` dependency from `composer.lock`.
- **Implemented:** `#[Locked]` Livewire attribute across components for read-only properties.
- **Added:** Feature tests to ensure locked properties cannot be tampered with.

.junie/mcp/mcp.json

@@ -1,9 +1,9 @@
 {
     "mcpServers": {
         "laravel-boost": {
-            "command": "vendor/bin/sail",
+            "command": "/usr/bin/php",
             "args": [
-                "artisan",
+                "/var/home/user/Code/einundzwanzig-app/artisan",
                 "boost:mcp"
             ]
         }