From 478a3da4225c18bd0561dbb747e4e1591215fbdd Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 6 Mar 2026 04:10:27 +0000
Subject: [PATCH 1/6] Initial plan


From 7ed8bbea2288f3af02ccf8ffd45cac778239a458 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 6 Mar 2026 04:13:01 +0000
Subject: [PATCH 2/6] =?UTF-8?q?feat:=20=E4=BD=9C=E6=A5=AD=E8=A8=88?=
 =?UTF-8?q?=E7=94=BB=E3=81=AE=E6=95=B4=E7=90=86?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Docs CI導入に向けた進め方を共有するため。
事前確認を踏まえた最小変更の計画を明確化した。

Co-authored-by: LevelCapTech <99854263+LevelCapTech@users.noreply.github.com>
---
 package-lock.json | 18 ------------------
 1 file changed, 18 deletions(-)

diff --git a/package-lock.json b/package-lock.json
index b20b5324..303148f1 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -21826,24 +21826,6 @@
         }
       }
     },
-    "node_modules/tailwindcss/node_modules/yaml": {
-      "version": "2.8.2",
-      "resolved": "https://registry.npmjs.org/yaml/-/yaml-2.8.2.tgz",
-      "integrity": "sha512-mplynKqc1C2hTVYxd0PU2xQAc22TI1vShAYGksCCfxbn/dFwnHTNi1bvYsBTkhdUNtGIf5xNOg938rrSSYvS9A==",
-      "dev": true,
-      "license": "ISC",
-      "optional": true,
-      "peer": true,
-      "bin": {
-        "yaml": "bin.mjs"
-      },
-      "engines": {
-        "node": ">= 14.6"
-      },
-      "funding": {
-        "url": "https://github.com/sponsors/eemeli"
-      }
-    },
     "node_modules/tapable": {
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/tapable/-/tapable-2.3.0.tgz",

From e2150796088b68e00c34c732d5f82358533aa921 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 6 Mar 2026 04:16:49 +0000
Subject: [PATCH 3/6] =?UTF-8?q?feat:=20Docs=E5=90=91=E3=81=91CI=E3=81=AE?=
 =?UTF-8?q?=E5=B0=8E=E5=85=A5?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

MarkdownlintとMermaid図検証をReviewdogで通知するため。
package-lock.jsonの誤差分を戻し、設定とワークフローを追加した。

Co-authored-by: LevelCapTech <99854263+LevelCapTech@users.noreply.github.com>
---
 .github/workflows/markdownlint.yml | 40 ++++++++++++
 .github/workflows/mermaid-lint.yml | 97 ++++++++++++++++++++++++++++++
 .markdownlint.json                 |  4 ++
 package-lock.json                  | 18 ++++++
 4 files changed, 159 insertions(+)
 create mode 100644 .github/workflows/markdownlint.yml
 create mode 100644 .github/workflows/mermaid-lint.yml
 create mode 100644 .markdownlint.json

diff --git a/.github/workflows/markdownlint.yml b/.github/workflows/markdownlint.yml
new file mode 100644
index 00000000..4109cc54
--- /dev/null
+++ b/.github/workflows/markdownlint.yml
@@ -0,0 +1,40 @@
+name: markdownlint
+
+on:
+  pull_request:
+    paths:
+      - "docs/**/*.md"
+      - ".github/**/*.md"
+  push:
+    paths:
+      - "docs/**/*.md"
+      - ".github/**/*.md"
+
+jobs:
+  markdownlint:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      pull-requests: write
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      - name: Install tools
+        run: |
+          npm install -g markdownlint-cli
+          npm install -g reviewdog
+
+      - name: Markdown lint
+        run: |
+          markdownlint "docs/**/*.md" ".github/**/*.md" \
+            | reviewdog \
+              -f=markdownlint \
+              -name="Markdownチェック" \
+              -reporter=github-pr-review \
+              -level=warning
diff --git a/.github/workflows/mermaid-lint.yml b/.github/workflows/mermaid-lint.yml
new file mode 100644
index 00000000..998e7cf3
--- /dev/null
+++ b/.github/workflows/mermaid-lint.yml
@@ -0,0 +1,97 @@
+name: mermaid-lint
+
+on:
+  pull_request:
+    paths:
+      - "docs/**/*.md"
+      - ".github/**/*.md"
+
+jobs:
+  mermaid:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      pull-requests: write
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      - name: Install tools
+        run: |
+          npm install -g @mermaid-js/mermaid-cli
+          npm install -g reviewdog
+
+      - name: Extract Mermaid blocks
+        run: |
+          mkdir -p tmp
+          node <<'EOF'
+          const fs = require('fs')
+          const path = require('path')
+
+          let i = 0
+          const mapPath = path.join('tmp', 'map.txt')
+          fs.writeFileSync(mapPath, '')
+
+          function walk(dir) {
+            if (!fs.existsSync(dir)) return
+            fs.readdirSync(dir).forEach((file) => {
+              const full = path.join(dir, file)
+              if (fs.statSync(full).isDirectory()) walk(full)
+              else if (full.endsWith('.md')) processFile(full)
+            })
+          }
+
+          function processFile(file) {
+            const lines = fs.readFileSync(file, 'utf8').split('\n')
+            let inside = false
+            let buffer = []
+            let startLine = 0
+
+            lines.forEach((line, idx) => {
+              if (line.startsWith('```mermaid')) {
+                inside = true
+                buffer = []
+                startLine = idx + 1
+                return
+              }
+
+              if (inside && line.startsWith('```')) {
+                inside = false
+                const name = `tmp/diagram-${++i}.mmd`
+                fs.writeFileSync(name, buffer.join('\n'))
+                fs.appendFileSync(mapPath, `${name}:${file}:${startLine}\n`)
+                return
+              }
+
+              if (inside) buffer.push(line)
+            })
+          }
+
+          walk('docs')
+          walk('.github')
+          EOF
+
+      - name: Validate Mermaid diagrams
+        run: |
+          : > result.txt
+
+          if [ -s tmp/map.txt ]; then
+            while IFS=":" read -r mmd src line; do
+              if ! mmdc -i "$mmd" -o "$mmd.svg"; then
+                echo "$src:$line: Mermaid図の構文エラー" >> result.txt
+              fi
+            done < tmp/map.txt
+          fi
+
+      - name: Report via reviewdog
+        run: |
+          cat result.txt | reviewdog \
+            -efm="%f:%l: %m" \
+            -name="Mermaid図チェック" \
+            -reporter=github-pr-review \
+            -level=error
diff --git a/.markdownlint.json b/.markdownlint.json
new file mode 100644
index 00000000..26593a22
--- /dev/null
+++ b/.markdownlint.json
@@ -0,0 +1,4 @@
+{
+  "MD013": false,
+  "MD033": false
+}
diff --git a/package-lock.json b/package-lock.json
index 303148f1..b20b5324 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -21826,6 +21826,24 @@
         }
       }
     },
+    "node_modules/tailwindcss/node_modules/yaml": {
+      "version": "2.8.2",
+      "resolved": "https://registry.npmjs.org/yaml/-/yaml-2.8.2.tgz",
+      "integrity": "sha512-mplynKqc1C2hTVYxd0PU2xQAc22TI1vShAYGksCCfxbn/dFwnHTNi1bvYsBTkhdUNtGIf5xNOg938rrSSYvS9A==",
+      "dev": true,
+      "license": "ISC",
+      "optional": true,
+      "peer": true,
+      "bin": {
+        "yaml": "bin.mjs"
+      },
+      "engines": {
+        "node": ">= 14.6"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/eemeli"
+      }
+    },
     "node_modules/tapable": {
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/tapable/-/tapable-2.3.0.tgz",

From d7570626e955f210fdc3319d6421389d8e0a80d1 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 6 Mar 2026 04:18:56 +0000
Subject: [PATCH 4/6] =?UTF-8?q?fix:=20reviewdog=E5=B0=8E=E5=85=A5=E3=81=AE?=
 =?UTF-8?q?=E5=9B=BA=E5=AE=9A=E5=8C=96?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

reviewdogのセットアップを公式アクションに切り替えるため。
lintツールのバージョンを固定し、コメント用トークンを設定した。

Co-authored-by: LevelCapTech <99854263+LevelCapTech@users.noreply.github.com>
---
 .github/workflows/markdownlint.yml | 10 ++++++++--
 .github/workflows/mermaid-lint.yml | 22 +++++++++++++++-------
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/.github/workflows/markdownlint.yml b/.github/workflows/markdownlint.yml
index 4109cc54..9846537a 100644
--- a/.github/workflows/markdownlint.yml
+++ b/.github/workflows/markdownlint.yml
@@ -27,8 +27,12 @@ jobs:
 
       - name: Install tools
         run: |
-          npm install -g markdownlint-cli
-          npm install -g reviewdog
+          npm install -g markdownlint-cli@0.48.0
+
+      - name: Setup reviewdog
+        uses: reviewdog/action-setup@v1
+        with:
+          reviewdog_version: v0.21.0
 
       - name: Markdown lint
         run: |
@@ -38,3 +42,5 @@ jobs:
               -name="Markdownチェック" \
               -reporter=github-pr-review \
               -level=warning
+        env:
+          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/mermaid-lint.yml b/.github/workflows/mermaid-lint.yml
index 998e7cf3..7374a84b 100644
--- a/.github/workflows/mermaid-lint.yml
+++ b/.github/workflows/mermaid-lint.yml
@@ -23,8 +23,12 @@ jobs:
 
       - name: Install tools
         run: |
-          npm install -g @mermaid-js/mermaid-cli
-          npm install -g reviewdog
+          npm install -g @mermaid-js/mermaid-cli@11.12.0
+
+      - name: Setup reviewdog
+        uses: reviewdog/action-setup@v1
+        with:
+          reviewdog_version: v0.21.0
 
       - name: Extract Mermaid blocks
         run: |
@@ -90,8 +94,12 @@ jobs:
 
       - name: Report via reviewdog
         run: |
-          cat result.txt | reviewdog \
-            -efm="%f:%l: %m" \
-            -name="Mermaid図チェック" \
-            -reporter=github-pr-review \
-            -level=error
+          if [ -s result.txt ]; then
+            cat result.txt | reviewdog \
+              -efm="%f:%l: %m" \
+              -name="Mermaid図チェック" \
+              -reporter=github-pr-review \
+              -level=error
+          fi
+        env:
+          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}

From 8be9f681a8fd7bbd8a7d1eeae808c34141e212ff Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 6 Mar 2026 04:19:58 +0000
Subject: [PATCH 5/6] =?UTF-8?q?fix:=20lint=E5=87=BA=E5=8A=9B=E5=87=A6?=
 =?UTF-8?q?=E7=90=86=E3=81=AE=E8=AA=BF=E6=95=B4?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

markdownlintの結果を確実にreviewdogへ渡すため。
Mermaid図検証の出力詳細とカウンタ名を明確化した。

Co-authored-by: LevelCapTech <99854263+LevelCapTech@users.noreply.github.com>
---
 .github/workflows/markdownlint.yml | 12 ++++++------
 .github/workflows/mermaid-lint.yml |  9 +++++----
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/.github/workflows/markdownlint.yml b/.github/workflows/markdownlint.yml
index 9846537a..b6a5eeac 100644
--- a/.github/workflows/markdownlint.yml
+++ b/.github/workflows/markdownlint.yml
@@ -36,11 +36,11 @@ jobs:
 
       - name: Markdown lint
         run: |
-          markdownlint "docs/**/*.md" ".github/**/*.md" \
-            | reviewdog \
-              -f=markdownlint \
-              -name="Markdownチェック" \
-              -reporter=github-pr-review \
-              -level=warning
+          markdownlint "docs/**/*.md" ".github/**/*.md" > markdownlint.txt || true
+          cat markdownlint.txt | reviewdog \
+            -f=markdownlint \
+            -name="Markdownチェック" \
+            -reporter=github-pr-review \
+            -level=warning
         env:
           REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/mermaid-lint.yml b/.github/workflows/mermaid-lint.yml
index 7374a84b..6cf5b50d 100644
--- a/.github/workflows/mermaid-lint.yml
+++ b/.github/workflows/mermaid-lint.yml
@@ -37,7 +37,7 @@ jobs:
           const fs = require('fs')
           const path = require('path')
 
-          let i = 0
+          let diagramCounter = 0
           const mapPath = path.join('tmp', 'map.txt')
           fs.writeFileSync(mapPath, '')
 
@@ -66,7 +66,7 @@ jobs:
 
               if (inside && line.startsWith('```')) {
                 inside = false
-                const name = `tmp/diagram-${++i}.mmd`
+                const name = `tmp/diagram-${++diagramCounter}.mmd`
                 fs.writeFileSync(name, buffer.join('\n'))
                 fs.appendFileSync(mapPath, `${name}:${file}:${startLine}\n`)
                 return
@@ -86,8 +86,9 @@ jobs:
 
           if [ -s tmp/map.txt ]; then
             while IFS=":" read -r mmd src line; do
-              if ! mmdc -i "$mmd" -o "$mmd.svg"; then
-                echo "$src:$line: Mermaid図の構文エラー" >> result.txt
+              if ! output=$(mmdc -i "$mmd" -o "$mmd.svg" 2>&1); then
+                compact=$(printf "%s" "$output" | tr '\n' ' ')
+                echo "$src:$line: Mermaid図の構文エラー: $compact" >> result.txt
               fi
             done < tmp/map.txt
           fi

From a9592d6dfdbd8a507887126467e13adcd09ca3cb Mon Sep 17 00:00:00 2001
From: Yoshio Nishiyama <nishiyama@lvcap.jp>
Date: Sat, 7 Mar 2026 03:36:08 +0000
Subject: [PATCH 6/6] =?UTF-8?q?config:=20markdownlint=E3=82=92=E4=B8=A6?=
 =?UTF-8?q?=E5=88=97=E5=8C=96?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .github/workflows/markdownlint.yml | 136 +++++++++++++++++++---
 .github/workflows/mermaid-lint.yml | 175 ++++++++++++++++++++++++-----
 2 files changed, 267 insertions(+), 44 deletions(-)

diff --git a/.github/workflows/markdownlint.yml b/.github/workflows/markdownlint.yml
index b6a5eeac..507aacd1 100644
--- a/.github/workflows/markdownlint.yml
+++ b/.github/workflows/markdownlint.yml
@@ -1,7 +1,8 @@
-name: markdownlint
+name: Markdownチェック（reviewdog）
 
 on:
   pull_request:
+    types: [opened, synchronize, reopened, ready_for_review]
     paths:
       - "docs/**/*.md"
       - ".github/**/*.md"
@@ -10,8 +11,16 @@ on:
       - "docs/**/*.md"
       - ".github/**/*.md"
 
+permissions:
+  contents: read
+
+concurrency:
+  group: markdownlint-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
-  markdownlint:
+  markdownlint-pr:
+    if: github.event_name == 'pull_request'
     runs-on: ubuntu-latest
 
     permissions:
@@ -19,28 +28,127 @@ jobs:
       pull-requests: write
 
     steps:
-      - uses: actions/checkout@v4
+      - name: Checkout repository
+        uses: actions/checkout@v6
 
-      - uses: actions/setup-node@v4
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
         with:
-          node-version: 20
+          node-version: "24"
 
       - name: Install tools
+        run: npm install -g markdownlint-cli@0.48.0
+
+      - name: Log goコマンド確認開始
+        run: echo "goコマンドの存在を確認します" >&2
+
+      - name: Check Go availability
         run: |
-          npm install -g markdownlint-cli@0.48.0
+          if ! command -v go >/dev/null 2>&1; then
+            echo "goコマンドが見つからないためジョブを失敗扱いにします" >&2
+            exit 1
+          fi
 
-      - name: Setup reviewdog
-        uses: reviewdog/action-setup@v1
-        with:
-          reviewdog_version: v0.21.0
+      - name: Install reviewdog
+        run: |
+          go install github.com/reviewdog/reviewdog/cmd/reviewdog@v0.21.0
+          echo "$HOME/go/bin" >> "$GITHUB_PATH"
+
+      - name: Log markdownlint開始
+        run: echo "markdownlintとreviewdogを実行します" >&2
 
       - name: Markdown lint
+        env:
+          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
-          markdownlint "docs/**/*.md" ".github/**/*.md" > markdownlint.txt || true
-          cat markdownlint.txt | reviewdog \
+          set -eu
+          # 複数コマンドをパイプで繋いでいないため pipefail は省略
+          exit_code=0
+          markdownlint "docs/**/*.md" ".github/**/*.md" > markdownlint.txt || exit_code=$?
+          reviewdog_exit=0
+          reviewdog < markdownlint.txt \
             -f=markdownlint \
             -name="Markdownチェック" \
-            -reporter=github-pr-review \
-            -level=warning
+            -reporter="github-pr-review" \
+            -level=warning || reviewdog_exit=$?
+          # markdownlint: 1=lint違反, 2以上=実行エラー
+          # reviewdog: 0=成功（PRコメント/チェックの投稿が成功）
+          if [ "$reviewdog_exit" -ne 0 ]; then
+            echo "reviewdogが失敗しました: exit code ${reviewdog_exit}" >&2
+            exit "$reviewdog_exit"
+          fi
+          # exit_code=1 は reviewdog で通知済みのため成功扱い
+          if [ "$exit_code" -gt 1 ]; then
+            echo "markdownlintが失敗しました: exit code ${exit_code}" >&2
+            exit "$exit_code"
+          fi
+
+      - name: Log markdownlint完了
+        run: echo "markdownlintとreviewdogの処理が完了しました" >&2
+
+  markdownlint-push:
+    if: github.event_name == 'push'
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      checks: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: "24"
+
+      - name: Install tools
+        run: npm install -g markdownlint-cli@0.48.0
+
+      - name: Log goコマンド確認開始
+        run: echo "goコマンドの存在を確認します" >&2
+
+      - name: Check Go availability
+        run: |
+          if ! command -v go >/dev/null 2>&1; then
+            echo "goコマンドが見つからないためジョブを失敗扱いにします" >&2
+            exit 1
+          fi
+
+      - name: Install reviewdog
+        run: |
+          go install github.com/reviewdog/reviewdog/cmd/reviewdog@v0.21.0
+          echo "$HOME/go/bin" >> "$GITHUB_PATH"
+
+      - name: Log markdownlint開始
+        run: echo "markdownlintとreviewdogを実行します" >&2
+
+      - name: Markdown lint
         env:
           REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -eu
+          # 複数コマンドをパイプで繋いでいないため pipefail は省略
+          exit_code=0
+          markdownlint "docs/**/*.md" ".github/**/*.md" > markdownlint.txt || exit_code=$?
+          reviewdog_exit=0
+          reviewdog < markdownlint.txt \
+            -f=markdownlint \
+            -name="Markdownチェック" \
+            -reporter="github-check" \
+            -level=warning || reviewdog_exit=$?
+          # markdownlint: 1=lint違反, 2以上=実行エラー
+          # reviewdog: 0=成功（PRコメント/チェックの投稿が成功）
+          if [ "$reviewdog_exit" -ne 0 ]; then
+            echo "reviewdogが失敗しました: exit code ${reviewdog_exit}" >&2
+            exit "$reviewdog_exit"
+          fi
+          # exit_code=1 は reviewdog で通知済みのため成功扱い
+          if [ "$exit_code" -gt 1 ]; then
+            echo "markdownlintが失敗しました: exit code ${exit_code}" >&2
+            exit "$exit_code"
+          fi
+
+      - name: Log markdownlint完了
+        run: echo "markdownlintとreviewdogの処理が完了しました" >&2
diff --git a/.github/workflows/mermaid-lint.yml b/.github/workflows/mermaid-lint.yml
index 6cf5b50d..6b041cc3 100644
--- a/.github/workflows/mermaid-lint.yml
+++ b/.github/workflows/mermaid-lint.yml
@@ -1,11 +1,19 @@
-name: mermaid-lint
+name: Mermaid図チェック（reviewdog）
 
 on:
   pull_request:
+    types: [opened, synchronize, reopened, ready_for_review]
     paths:
       - "docs/**/*.md"
       - ".github/**/*.md"
 
+permissions:
+  contents: read
+
+concurrency:
+  group: mermaid-lint-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   mermaid:
     runs-on: ubuntu-latest
@@ -15,20 +23,52 @@ jobs:
       pull-requests: write
 
     steps:
-      - uses: actions/checkout@v4
+      - name: Checkout repository
+        uses: actions/checkout@v6
 
-      - uses: actions/setup-node@v4
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
         with:
-          node-version: 20
+          node-version: "24"
 
-      - name: Install tools
+      - name: Log Mermaid CLIインストール開始
+        run: echo "Mermaid CLIをインストールします" >&2
+
+      - name: Install Mermaid CLI
         run: |
+          set -e
           npm install -g @mermaid-js/mermaid-cli@11.12.0
 
-      - name: Setup reviewdog
-        uses: reviewdog/action-setup@v1
-        with:
-          reviewdog_version: v0.21.0
+      - name: Log Mermaid CLIインストール完了
+        run: echo "Mermaid CLIのインストールが完了しました" >&2
+
+      - name: Log mmdcコマンド確認開始
+        run: echo "mmdcコマンドの存在を確認します" >&2
+
+      - name: Check mmdc availability
+        run: |
+          if ! command -v mmdc >/dev/null 2>&1; then
+            echo "mmdcコマンドが見つからないためジョブを失敗扱いにします" >&2
+            exit 1
+          fi
+
+      - name: Log goコマンド確認開始
+        run: echo "goコマンドの存在を確認します" >&2
+
+      - name: Check Go availability
+        run: |
+          if ! command -v go >/dev/null 2>&1; then
+            echo "goコマンドが見つからないためジョブを失敗扱いにします" >&2
+            exit 1
+          fi
+
+      - name: Install reviewdog
+        run: |
+          go install github.com/reviewdog/reviewdog/cmd/reviewdog@v0.21.0
+          echo "$HOME/go/bin" >> "$GITHUB_PATH"
+
+      - name: Log Mermaidブロック抽出開始
+        run: echo "Mermaidブロック抽出を開始します" >&2
 
       - name: Extract Mermaid blocks
         run: |
@@ -37,16 +77,27 @@ jobs:
           const fs = require('fs')
           const path = require('path')
 
-          let diagramCounter = 0
+          // Mermaid抽出ファイルと元Markdownの対応を「抽出ファイル:元ファイル:開始行」形式で記録
+          // 例: tmp/diagram-1.mmd:docs/example.md:42
           const mapPath = path.join('tmp', 'map.txt')
           fs.writeFileSync(mapPath, '')
 
+          // Mermaidブロックの件数
+          let index = 0
+
+          // 指定ディレクトリ以下のMarkdownを探索
           function walk(dir) {
             if (!fs.existsSync(dir)) return
-            fs.readdirSync(dir).forEach((file) => {
-              const full = path.join(dir, file)
-              if (fs.statSync(full).isDirectory()) walk(full)
-              else if (full.endsWith('.md')) processFile(full)
+            fs.readdirSync(dir).forEach((entry) => {
+              const full = path.join(dir, entry)
+              const stat = fs.statSync(full)
+              if (stat.isDirectory()) {
+                walk(full)
+                return
+              }
+              if (full.endsWith('.md')) {
+                processFile(full)
+              }
             })
           }
 
@@ -57,16 +108,19 @@ jobs:
             let startLine = 0
 
             lines.forEach((line, idx) => {
-              if (line.startsWith('```mermaid')) {
+              const trimmed = line.trim()
+              // Mermaidブロックの開始
+              if (!inside && trimmed.startsWith('```mermaid')) {
                 inside = true
                 buffer = []
                 startLine = idx + 1
                 return
               }
 
-              if (inside && line.startsWith('```')) {
+              // Mermaidブロックの終了
+              if (inside && trimmed.startsWith('```')) {
                 inside = false
-                const name = `tmp/diagram-${++diagramCounter}.mmd`
+                const name = `tmp/diagram-${++index}.mmd`
                 fs.writeFileSync(name, buffer.join('\n'))
                 fs.appendFileSync(mapPath, `${name}:${file}:${startLine}\n`)
                 return
@@ -74,33 +128,94 @@ jobs:
 
               if (inside) buffer.push(line)
             })
+
+            // ファイル末尾まで到達しても終了フェンスが無い場合（閉じ忘れ）もブロックを検証対象に含める
+            if (inside) {
+              const name = `tmp/diagram-${++index}.mmd`
+              fs.writeFileSync(name, buffer.join('\n'))
+              fs.appendFileSync(mapPath, `${name}:${file}:${startLine}\n`)
+            }
           }
 
           walk('docs')
           walk('.github')
+          console.error(`抽出したMermaid図: ${index}件`)
           EOF
 
+      - name: Log Mermaidブロック抽出完了
+        run: echo "Mermaidブロック抽出が完了しました" >&2
+
+      - name: Log Mermaid図検証開始
+        run: echo "Mermaid図の検証を開始します" >&2
+
       - name: Validate Mermaid diagrams
         run: |
-          : > result.txt
-
+          : > tmp/result.txt
+          MAX_ERROR_LENGTH=500
+          # Mermaid CLIの実行環境起因エラー（Puppeteer/ブラウザ起動失敗等）を判定するための正規表現パターン
+          # 各要素は正規表現として評価するため、必要に応じてメタ文字を使用/エスケープする
+          # 出力メッセージの大文字小文字揺れを吸収するため、grepは -i を使用する
+          MMD_CLI_EXEC_ERROR_PATTERNS=(
+            # Puppeteer関連のエラー文言（例: "Error: Puppeteer failed to connect"）
+            'error.*puppeteer'
+            # 実行ファイル未検出（例: "Executable doesn't exist at /path/to/chrome"）
+            "executable doesn't exist"
+            # browser executable.*exist は実行ファイル探索時の存在エラー検知を意図（例: "browser executable doesn't exist"）
+            'browser executable.*exist'
+            # 起動失敗の共通文言（例: "Failed to launch the browser process!"）
+            'failed to launch'
+            # browsertype.launch のドットはリテラルとして扱う（例: "browserType.launch: Executable doesn't exist ..."）
+            'browsertype\.launch'
+          )
+          # 配列要素を | で連結して正規表現文字列を生成（例: error.*puppeteer|...）
+          MMD_CLI_EXEC_ERROR_REGEX=$(IFS='|'; printf '%s' "${MMD_CLI_EXEC_ERROR_PATTERNS[*]}")
+          cat <<'JSON' > tmp/puppeteer-config.json
+          {
+            "args": ["--no-sandbox", "--disable-setuid-sandbox"]
+          }
+          JSON
           if [ -s tmp/map.txt ]; then
+            mmdc_exec_error=0
+            mmdc_exec_summary=""
             while IFS=":" read -r mmd src line; do
-              if ! output=$(mmdc -i "$mmd" -o "$mmd.svg" 2>&1); then
-                compact=$(printf "%s" "$output" | tr '\n' ' ')
-                echo "$src:$line: Mermaid図の構文エラー: $compact" >> result.txt
+              if [ -z "${mmd}" ]; then
+                continue
+              fi
+              if ! output=$(mmdc -p tmp/puppeteer-config.json -i "${mmd}" -o "${mmd}.svg" 2>&1); then
+                summary=$(printf "%s" "${output}" | tr '\n' ' ' | cut -c1-${MAX_ERROR_LENGTH})
+                if printf "%s" "${output}" | grep -qiE "${MMD_CLI_EXEC_ERROR_REGEX}"; then
+                  mmdc_exec_error=1
+                  mmdc_exec_summary="${summary}"
+                  echo "mmdcの実行に失敗しました: ${summary}" >&2
+                  # 実行環境エラーは全図に影響するため、以降の検証を中断してジョブを失敗扱いにする
+                  break
+                fi
+                echo "${src}:${line}: Mermaid図の構文検証に失敗しました: ${summary}" >> tmp/result.txt
               fi
             done < tmp/map.txt
+            if [ "${mmdc_exec_error}" -ne 0 ]; then
+              echo "Mermaid CLIの実行エラーのためジョブを失敗扱いにします: ${mmdc_exec_summary}" >&2
+              exit 1
+            fi
+          else
+            echo "Mermaidブロックが見つからなかったため検証をスキップします" >&2
           fi
 
+      - name: Log Mermaid図検証完了
+        run: echo "Mermaid図の検証が完了しました" >&2
+
+      - name: Log reviewdog通知開始
+        run: echo "reviewdogで結果を通知します" >&2
+
       - name: Report via reviewdog
-        run: |
-          if [ -s result.txt ]; then
-            cat result.txt | reviewdog \
-              -efm="%f:%l: %m" \
-              -name="Mermaid図チェック" \
-              -reporter=github-pr-review \
-              -level=error
-          fi
         env:
           REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          reviewdog < tmp/result.txt \
+            -efm="%f:%l: %m" \
+            -name="Mermaid図チェック" \
+            -reporter=github-pr-review \
+            -level=error
+
+      - name: Log reviewdog通知完了
+        run: echo "reviewdogの通知処理が完了しました" >&2