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>

docker/php/Dockerfile

@@ -0,0 +1,36 @@
+FROM php:8.2-fpm
+
+# 必要なパッケージのインストール
+RUN apt-get update && apt-get install -y \
+    git \
+    curl \
+    libpng-dev \
+    libonig-dev \
+    libxml2-dev \
+    libzip-dev \
+    zip \
+    unzip \
+    && docker-php-ext-install pdo_mysql mbstring exif pcntl bcmath gd zip
+
+# Composerのインストール
+COPY --from=composer:latest /usr/bin/composer /usr/bin/composer
+
+# Node.jsとnpmのインストール（Laravel Mixやvite用）
+RUN curl -fsSL https://deb.nodesource.com/setup_20.x | bash - \
+    && apt-get install -y nodejs
+
+# 作業ディレクトリの設定
+WORKDIR /var/www/html
+
+# パーミッション設定
+RUN chown -R www-data:www-data /var/www/html \
+    && chmod -R 755 /var/www/html
+
+# クリーンアップ
+RUN apt-get clean && rm -rf /var/lib/apt/lists/*
+
+# ユーザーをwww-dataに切り替え
+USER www-data
+
+# PHP-FPMを実行
+CMD ["php-fpm"]