Add explicit GITHUB_TOKEN permissions to workflows for security

Co-authored-by: huangyiirene <7665279+huangyiirene@users.noreply.github.com>

Author: Copilot

.github/workflows/ci.yml

@@ -12,6 +12,8 @@ jobs:
   build:
     name: Build and Test
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
 
     steps:
       - name: Checkout code

.github/workflows/link-check.yml

@@ -15,6 +15,8 @@ jobs:
   link-check:
     name: Check Links
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
 
     steps:
       - name: Checkout code

.github/workflows/preview.yml

@@ -8,6 +8,9 @@ jobs:
   preview-info:
     name: Preview Information
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: write
 
     steps:
       - name: Checkout code