diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000..8890c37
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,12 @@
+version: 2
+
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    open-pull-requests-limit: 5
+    labels:
+      - "type: dependencies"
+    commit-message:
+      prefix: "ci"
diff --git a/.github/workflows/preview-labels.yml b/.github/workflows/preview-labels.yml
new file mode 100644
index 0000000..e9ed549
--- /dev/null
+++ b/.github/workflows/preview-labels.yml
@@ -0,0 +1,62 @@
+name: Preview organization labels
+
+on:
+  workflow_dispatch:
+    inputs:
+      repository:
+        description: "只预览指定仓库；留空预览全部可见仓库"
+        required: false
+        type: string
+        default: ""
+
+  pull_request:
+    paths:
+      - ".github/labels.yml"
+      - ".github/actions/sync-labels/**"
+      - ".github/workflows/preview-labels.yml"
+      - ".github/workflows/sync-labels.yml"
+
+  push:
+    branches:
+      - main
+    paths:
+      - ".github/labels.yml"
+      - ".github/actions/sync-labels/**"
+      - ".github/workflows/preview-labels.yml"
+      - ".github/workflows/sync-labels.yml"
+
+  schedule:
+    # 每周一 UTC 03:17 检查公开可见仓库的标签漂移。
+    - cron: "17 3 * * 1"
+
+permissions:
+  contents: read
+  issues: read
+
+concurrency:
+  group: preview-organization-labels-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  preview-labels:
+    name: Preview organization label changes
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+
+    steps:
+      - name: Checkout governance repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
+
+      - name: Preview MathArts label synchronization
+        uses: ./.github/actions/sync-labels
+        with:
+          token: ${{ github.token }}
+          owner: ${{ github.repository_owner }}
+          config_file: ".github/labels.yml"
+          dry_run: "true"
+          repository: >-
+            ${{ github.event_name == 'workflow_dispatch'
+                && inputs.repository
+                || '' }}
diff --git a/.github/workflows/sync-labels.yml b/.github/workflows/sync-labels.yml
index 326c244..0fe74ec 100644
--- a/.github/workflows/sync-labels.yml
+++ b/.github/workflows/sync-labels.yml
@@ -1,83 +1,47 @@
-name: Sync organization labels
+name: Apply organization labels
 
 on:
   workflow_dispatch:
     inputs:
-      dry_run:
-        description: "仅预览变更；关闭后才会实际修改标签"
-        required: true
-        type: boolean
-        default: true
-
       repository:
         description: "只同步指定仓库；留空同步全部仓库"
         required: false
         type: string
         default: ""
 
-  push:
-    branches:
-      - main
-    paths:
-      - ".github/labels.yml"
-      - ".github/actions/sync-labels/**"
-      - ".github/workflows/sync-labels.yml"
-
-  schedule:
-    # 每周一 UTC 03:17 预览标签漂移，不自动写入仓库。
-    - cron: "17 3 * * 1"
+      confirm_apply:
+        description: "确认执行真实标签变更"
+        required: true
+        type: boolean
+        default: false
 
 permissions:
   contents: read
 
 concurrency:
-  group: sync-organization-labels
+  group: apply-organization-labels
   cancel-in-progress: false
 
 jobs:
-  sync-labels:
-    name: Preview or synchronize organization labels
+  apply-labels:
+    name: Apply organization label changes
+    if: ${{ github.ref == 'refs/heads/main' && inputs.confirm_apply }}
     runs-on: ubuntu-latest
     timeout-minutes: 30
+    environment:
+      name: label-governance-production
 
     steps:
       - name: Checkout governance repository
-        uses: actions/checkout@v7
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
         with:
           persist-credentials: false
 
-      - name: Diagnose label sync token
-        shell: bash
-        env:
-          GH_TOKEN: ${{ secrets.LABEL_SYNC_TOKEN }}
-        run: |
-          set -euo pipefail
-
-          echo "Testing repository access..."
-          gh api \
-            -H "Accept: application/vnd.github+json" \
-            /repos/matharts/.github \
-            --jq '{full_name, private, archived, permissions}'
-
-          echo "Testing label read access..."
-          gh api \
-            -H "Accept: application/vnd.github+json" \
-            "/repos/matharts/.github/labels?per_page=1" \
-            --include
-
-      - name: Run MathArts label sync
+      - name: Apply MathArts label synchronization
         uses: ./.github/actions/sync-labels
         with:
-          token: ${{ secrets.LABEL_SYNC_TOKEN }}
+          token: ${{ secrets.LABEL_SYNC_WRITE_TOKEN }}
           owner: ${{ github.repository_owner }}
           config_file: ".github/labels.yml"
-
-          # Push 和定时任务只做预览。只有手动触发并关闭 dry_run 才实际写入。
-          dry_run: >-
-            ${{ github.event_name != 'workflow_dispatch'
-                || inputs.dry_run }}
-
-          repository: >-
-            ${{ github.event_name == 'workflow_dispatch'
-                && inputs.repository
-                || '' }}
+          dry_run: "false"
+          repository: ${{ inputs.repository }}
diff --git a/.github/workflows/validate-documentation.yml b/.github/workflows/validate-documentation.yml
index 8cbd5b9..43a95ab 100644
--- a/.github/workflows/validate-documentation.yml
+++ b/.github/workflows/validate-documentation.yml
@@ -42,7 +42,7 @@ jobs:
     timeout-minutes: 5
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v7
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
         with:
           persist-credentials: false
 
@@ -68,10 +68,10 @@ jobs:
     name: Lint Markdown
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
         with:
           persist-credentials: false
-      - uses: DavidAnson/markdownlint-cli2-action@v24
+      - uses: DavidAnson/markdownlint-cli2-action@8de2aa07cae85fd17c0b35642db70cf5495f1d25 # v24
         with:
           config: ".markdownlint-cli2.jsonc"
           globs: "**/*.md"
@@ -81,7 +81,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
         with:
           persist-credentials: false
 
@@ -99,10 +99,10 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 20
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
         with:
           persist-credentials: false
-      - uses: lycheeverse/lychee-action@v2
+      - uses: lycheeverse/lychee-action@e7477775783ea5526144ba13e8db5eec57747ce8 # v2
         with:
           args: >-
             --config lychee.toml
diff --git a/README.md b/README.md
index 996d42f..0e8f2ca 100644
--- a/README.md
+++ b/README.md
@@ -47,7 +47,12 @@ MathArts 的组织级标签由两个权威来源共同维护：
 
 标签同步只管理组织保留的 `type:*`、`status:*`、`priority:*`、`impact:*`、`process:*`、`resolution:*` 系列、贡献入口标签及其历史别名。项目仓库可以增加 `area:*`、`package:*`、`platform:*` 或其他项目特定标签，自动化会保留这些扩展标签。
 
-推送和定时任务只预览标签漂移。实际修改必须通过手动触发标签同步工作流，并明确关闭 Dry Run。
+标签自动化分为两个权限边界：
+
+* [`preview-labels.yml`](.github/workflows/preview-labels.yml) 在推送、定时任务或手动触发时使用只读 `github.token` 预览公开可见仓库的标签漂移，不读取跨仓库写令牌；
+* [`sync-labels.yml`](.github/workflows/sync-labels.yml) 只允许从 `main` 手动触发真实变更，并绑定 `label-governance-production` Environment。
+
+真实同步所需的 `LABEL_SYNC_WRITE_TOKEN` 必须配置为 `label-governance-production` 的 Environment Secret，而不是普通仓库 Secret。该 Environment 应在仓库设置中启用 Required reviewers，并禁止发起者自行批准。
 
 ## 维护原则