Add explicit permissions to workflows for security

Co-authored-by: PhantomDave <34485699+PhantomDave@users.noreply.github.com>

Author: Copilot

.github/workflows/backend-api.yml

@@ -20,6 +20,8 @@ jobs:
   build-and-lint:
     name: Build and Lint Backend API
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
 
     steps:
     - name: Checkout code

.github/workflows/backend-data.yml

@@ -20,6 +20,8 @@ jobs:
   build-and-lint:
     name: Build and Lint Backend Data
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
 
     steps:
     - name: Checkout code

.github/workflows/backend-library.yml

@@ -18,6 +18,8 @@ jobs:
   build-and-lint:
     name: Build and Lint Backend Library
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
 
     steps:
     - name: Checkout code

.github/workflows/frontend.yml

@@ -16,6 +16,8 @@ jobs:
   build-and-lint:
     name: Build and Lint Frontend
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
 
     steps:
     - name: Checkout code