diff --git a/.github/cspell.json b/.github/cspell.json
new file mode 100644
index 0000000000..0c872cb3c3
--- /dev/null
+++ b/.github/cspell.json
@@ -0,0 +1,109 @@
+{
+  "version": "0.2",
+  "language": "en",
+  "caseSensitive": false,
+  "words": [
+    "CakePHP",
+    "VitePress",
+    "php",
+    "datetime",
+    "varchar",
+    "postgresql",
+    "mysql",
+    "sqlite",
+    "webroot",
+    "csrf",
+    "xss",
+    "cakephp",
+    "bake",
+    "phinx",
+    "hasher",
+    "middlewares",
+    "namespaced",
+    "phpunit",
+    "composable",
+    "autowiring",
+    "stringable",
+    "arrayable",
+    "timestampable",
+    "paginator",
+    "Enqueue",
+    "dequeue",
+    "nullable",
+    "accessor",
+    "mutator",
+    "minphpversion",
+    "phpversion",
+    "XAMPP",
+    "WAMP",
+    "MAMP",
+    "controllername",
+    "actionname",
+    "Datamapper",
+    "webservices",
+    "nginx",
+    "apache",
+    "httpd",
+    "lighttpd",
+    "mbstring",
+    "simplexml",
+    "Laragon",
+    "composer",
+    "phar",
+    "paginate",
+    "startup",
+    "endfor",
+    "endwhile",
+    "sidebar",
+    "blocks",
+    "rewrite",
+    "before",
+    "called",
+    "sites",
+    "example",
+    "Classes",
+    "Redirect",
+    "Layout"
+  ],
+  "ignoreRegExpList": [
+    "\\$[a-zA-Z_][a-zA-Z0-9_]*",
+    "[a-zA-Z]+::[a-zA-Z]+",
+    "<[^>]+>",
+    "`[^`]+`",
+    "```[\\s\\S]*?```",
+    "\\b[A-Z][a-z]+(?:[A-Z][a-z]+)+\\b",
+    "\\b[a-z]+_[a-z_]+\\b",
+    "\\bhttps?:\\/\\/[^\\s]+",
+    "\\[[a-z]\\][a-z]+",
+    "\\b[A-Z][a-z]+\\b",
+    "\\b(true|false|null|while|for|if|else)\\b"
+  ],
+  "languageSettings": [
+    {
+      "languageId": "*",
+      "locale": "en",
+      "dictionaries": ["en", "softwareTerms", "php"]
+    },
+    {
+      "languageId": "*",
+      "locale": "ja",
+      "allowCompoundWords": true
+    }
+  ],
+  "overrides": [
+    {
+      "filename": "**/docs/ja/**/*.md",
+      "language": "ja",
+      "ignoreRegExpList": [
+        "[\\p{Script=Hiragana}\\p{Script=Katakana}\\p{Script=Han}]+"
+      ]
+    }
+  ],
+  "ignorePaths": [
+    "node_modules/**",
+    ".temp/**",
+    "dist/**",
+    "**/*.min.js",
+    "**/*.lock"
+  ]
+}
diff --git a/.github/markdownlint.json b/.github/markdownlint.json
new file mode 100644
index 0000000000..4327587dbf
--- /dev/null
+++ b/.github/markdownlint.json
@@ -0,0 +1,50 @@
+{
+  "default": true,
+  "heading-increment": false,
+  "no-hard-tabs": false,
+  "no-multiple-blanks": false,
+  "line-length": false,
+  "commands-show-output": false,
+  "blanks-around-headings": false,
+  "no-duplicate-heading": false,
+  "single-h1": false,
+  "no-trailing-punctuation": false,
+  "no-blanks-blockquote": false,
+  "list-marker-space": false,
+  "blanks-around-fences": false,
+  "blanks-around-lists": false,
+  "no-inline-html": {
+    "allowed_elements": [
+      "Badge",
+      "div",
+      "span",
+      "br",
+      "style",
+      "details",
+      "summary",
+      "table",
+      "thead",
+      "tbody",
+      "tr",
+      "th",
+      "td",
+      "img",
+      "a",
+      "svg",
+      "path",
+      "figure",
+      "p"
+    ]
+  },
+  "no-bare-urls": false,
+  "fenced-code-language": false,
+  "first-line-heading": false,
+  "code-block-style": false,
+  "single-trailing-newline": false,
+  "link-fragments": false,
+  "table-pipe-style": false,
+  "table-column-count": false,
+  "emphasis-style": false,
+  "table-column-style": false,
+  "descriptive-link-text": false
+}
diff --git a/.github/workflows/docs-validation.yml b/.github/workflows/docs-validation.yml
new file mode 100644
index 0000000000..a995ef186d
--- /dev/null
+++ b/.github/workflows/docs-validation.yml
@@ -0,0 +1,69 @@
+name: Documentation Validation
+
+on:
+  pull_request:
+    paths:
+      - 'docs/**'
+      - '.github/**'
+      - 'toc_*.json'
+      - 'config.js'
+
+jobs:
+  js-lint:
+    name: Validate JavaScript Files
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v5
+
+      - name: Validate config.js syntax
+        run: node --check config.js
+
+  json-lint:
+    name: Validate JSON Files
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v5
+
+      - name: Validate JSON syntax
+        run: |
+          for file in toc_*.json; do
+            if ! jq empty "$file" 2>/dev/null; then
+              echo "Invalid JSON: $file"
+              exit 1
+            fi
+            echo "✅ Valid: $file"
+          done
+
+  markdown-lint:
+    name: Lint Markdown
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v5
+
+      - name: Lint markdown files
+        uses: articulate/actions-markdownlint@v1
+        with:
+          config: .github/markdownlint.json
+          files: 'docs/**/*.md'
+          ignore: 'node_modules'
+
+  spell-check:
+    name: Spell Check
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v5
+
+      - name: Check spelling
+        uses: streetsidesoftware/cspell-action@v5
+        with:
+          files: 'docs/**/*.md'
+          config: '.github/cspell.json'
+          incremental_files_only: true