chore: Harden GitHub Actions workflow permissions

Add explicit permissions and persist-credentials: false to all workflows.

Without an explicit permissions block, GITHUB_TOKEN inherits the repo default (write-all). These CI workflows only need contents: read. The release workflow already declares contents: write at job level where needed.

persist-credentials: false prevents the token from lingering in .git/config for subsequent steps, reducing attack surface if a third-party action is compromised.

.github/workflows/code-checks.yml

@@ -6,6 +6,9 @@ on:
   pull_request:
     branches: [ main ]
 
+permissions:
+  contents: read
+
 jobs:
   lint-vital:
     name: Lint vitals
@@ -19,6 +22,8 @@ jobs:
     steps:
       - name: Checkout source code
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd #v6.0.2
+        with:
+          persist-credentials: false
       - name: Setup project and build environment
         uses: ./.github/actions/common-setup
 
@@ -37,6 +42,8 @@ jobs:
     steps:
       - name: Checkout source code
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd #v6.0.2
+        with:
+          persist-credentials: false
       - name: Setup project and build environment
         uses: ./.github/actions/common-setup
 
@@ -54,6 +61,8 @@ jobs:
     steps:
       - name: Checkout source code
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd #v6.0.2
+        with:
+          persist-credentials: false
       - name: Setup project and build environment
         uses: ./.github/actions/common-setup
 
@@ -66,5 +75,7 @@ jobs:
     steps:
       - name: Checkout source code
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd #v6.0.2
+        with:
+          persist-credentials: false
       - name: Validate metadata lengths
         run: bash fastlane/check_metadata_length.sh

.github/workflows/gradle-wrapper-validation.yml

@@ -8,10 +8,15 @@ on:
     branches:
       - main
 
+permissions:
+  contents: read
+
 jobs:
   validation:
     name: "Validation"
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd #v6.0.2
+        with:
+          persist-credentials: false
       - uses: gradle/actions/wrapper-validation@0723195856401067f7a2779048b490ace7a47d7c #v5.0.2

.github/workflows/release-tag.yml

@@ -11,6 +11,9 @@ on:
         type: boolean
         default: true
 
+permissions:
+  contents: read
+
 jobs:
   release-github:
     name: Create GitHub release
@@ -33,6 +36,7 @@ jobs:
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd #v6.0.2
         with:
           fetch-depth: 0
+          persist-credentials: false
 
       - name: Setup project and build environment
         uses: ./.github/actions/common-setup
@@ -108,6 +112,7 @@ jobs:
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd #v6.0.2
         with:
           fetch-depth: 0
+          persist-credentials: false
 
       - name: Setup project and build environment
         uses: ./.github/actions/common-setup