Implement ID-based routing and folder auto-generation from titles

Major features:
- Switch from slug-based to ID-based routing (/documents/123)
- Enable title editing with automatic slug/path regeneration
- Auto-generate folder structure from title slashes (e.g., Laravel/Livewire/Components)
- Persist sidebar folder open/close state using localStorage
- Remove slug unique constraint (ID routing makes it unnecessary)
- Implement recursive tree view with multi-level folder support

Architecture changes:
- DocumentService: Add generatePathAndSlug() for title-based path generation
- Routes: Change from {document:slug} to {document} for ID binding
- SidebarTree: Extract recursive rendering to partials/tree-item.blade.php
- Database: Remove unique constraint from documents.slug column

UI improvements:
- Display only last path component in sidebar (Components vs Laravel/Livewire/Components)
- Folder state persists across page navigation via localStorage
- Title field accepts slashes for folder organization

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/.env.example

@@ -0,0 +1,65 @@
+APP_NAME=Laravel
+APP_ENV=local
+APP_KEY=
+APP_DEBUG=true
+APP_URL=http://localhost
+
+APP_LOCALE=en
+APP_FALLBACK_LOCALE=en
+APP_FAKER_LOCALE=en_US
+
+APP_MAINTENANCE_DRIVER=file
+# APP_MAINTENANCE_STORE=database
+
+# PHP_CLI_SERVER_WORKERS=4
+
+BCRYPT_ROUNDS=12
+
+LOG_CHANNEL=stack
+LOG_STACK=single
+LOG_DEPRECATIONS_CHANNEL=null
+LOG_LEVEL=debug
+
+DB_CONNECTION=sqlite
+# DB_HOST=127.0.0.1
+# DB_PORT=3306
+# DB_DATABASE=laravel
+# DB_USERNAME=root
+# DB_PASSWORD=
+
+SESSION_DRIVER=database
+SESSION_LIFETIME=120
+SESSION_ENCRYPT=false
+SESSION_PATH=/
+SESSION_DOMAIN=null
+
+BROADCAST_CONNECTION=log
+FILESYSTEM_DISK=local
+QUEUE_CONNECTION=database
+
+CACHE_STORE=database
+# CACHE_PREFIX=
+
+MEMCACHED_HOST=127.0.0.1
+
+REDIS_CLIENT=phpredis
+REDIS_HOST=127.0.0.1
+REDIS_PASSWORD=null
+REDIS_PORT=6379
+
+MAIL_MAILER=log
+MAIL_SCHEME=null
+MAIL_HOST=127.0.0.1
+MAIL_PORT=2525
+MAIL_USERNAME=null
+MAIL_PASSWORD=null
+MAIL_FROM_ADDRESS="hello@example.com"
+MAIL_FROM_NAME="${APP_NAME}"
+
+AWS_ACCESS_KEY_ID=
+AWS_SECRET_ACCESS_KEY=
+AWS_DEFAULT_REGION=us-east-1
+AWS_BUCKET=
+AWS_USE_PATH_STYLE_ENDPOINT=false
+
+VITE_APP_NAME="${APP_NAME}"