chore(ci): add explicit GITHUB_TOKEN permissions to workflows (#114)

Add top-level `permissions` blocks to all workflow files to follow the
principle of least privilege and prepare for the upcoming default
read-only GITHUB_TOKEN enforcement.

Author: ilhan007

.github/workflows/ci.yml

@@ -6,6 +6,10 @@ on:
   pull_request:
     branches:
       - main
+
+permissions:
+  contents: read
+
 jobs:
   Test-and-Build:
     runs-on: ubuntu-latest

.github/workflows/deploy.yml

@@ -3,6 +3,10 @@ name: Deploy
 on:
   push:
     branches: [ main ]
+
+permissions:
+  contents: write
+
 jobs:
   deploy:
     runs-on: ubuntu-latest

.github/workflows/lint.yml

@@ -6,6 +6,10 @@ on:
   pull_request:
     branches:
       - main
+
+permissions:
+  contents: read
+
 jobs:
   check:
     runs-on: ubuntu-latest