feat: add permissions section to workflows for consistent access control

.github/workflows/astro-build-test.yml

@@ -12,6 +12,10 @@ on:
       - 'README.md'
       - 'docs/**'
 
+permissions:
+  contents: read
+  actions: read
+
 jobs:
   build-and-test:
     name: Build and Test Astro Project

.github/workflows/docker-scan.yml

@@ -18,6 +18,10 @@ on:
   schedule:
     - cron: '0 0 * * 0'  # Run weekly on Sunday at midnight
 
+permissions:
+  contents: read
+  actions: read
+
 jobs:
   scan:
     name: Scan Docker Image