fix(security): add explicit workflow permissions

Resolves CodeQL actions/missing-workflow-permissions alerts.
Adds explicit permissions blocks to all workflow YAML files.

Author: cl-efornaciari

.github/workflows/changesets.yml

@@ -5,6 +5,11 @@ on:
     branches:
       - main
 
+permissions:
+  contents: write
+  pull-requests: write
+  actions: write
+
 jobs:
   changesets:
     name: Changesets

.github/workflows/contracts.yml

@@ -7,6 +7,9 @@ on:
       - main
   pull_request:
 
+permissions:
+  contents: read
+
 jobs:
   contracts_run_ts_tests:
     name: Run Typescript Tests

.github/workflows/examples.yml

@@ -7,6 +7,9 @@ on:
       - main
   pull_request:
 
+permissions:
+  contents: read
+
 jobs:
   run_examples_tests:
     name: Run Tests

.github/workflows/golangci-lint.yml

@@ -3,6 +3,9 @@ name: golangci_lint
 on:
   push:
 
+permissions:
+  contents: read
+
 jobs:
   golangci-lint-version:
     name: Get golangci-lint version to from nix

.github/workflows/integration-tests-publish.yml

@@ -6,6 +6,9 @@ on:
     branches:
       - develop
 
+permissions:
+  contents: read
+
 env:
   ECR_TAG: ${{ secrets.QA_AWS_ACCOUNT_NUMBER }}.dkr.ecr.${{ secrets.QA_AWS_REGION }}.amazonaws.com/chainlink-starknet-tests:develop
 

.github/workflows/integration-tests-smoke.yml

@@ -19,6 +19,9 @@ concurrency:
   group: integration-tests-starknet-${{ github.ref }}
   cancel-in-progress: true
 
+permissions:
+  contents: read
+
 env:
   # for PR builds, ${{ github.sha }} is the temporary merge commit, we want the head commit instead
   SN_SHA: ${{ github.event.pull_request.head.sha || github.sha }}

.github/workflows/integration-tests-soak.yml

@@ -20,6 +20,9 @@ on:
         required: true
         type: string
 
+permissions:
+  contents: read
+
 env:
   TEST_LOG_LEVEL: debug
   CL_ECR: ${{ secrets.QA_AWS_ACCOUNT_NUMBER }}.dkr.ecr.${{ secrets.QA_AWS_REGION }}.amazonaws.com/chainlink

.github/workflows/integration_gauntlet.yml

@@ -7,6 +7,9 @@ on:
       - main
   pull_request:
 
+permissions:
+  contents: read
+
 jobs:
   gauntlet_eslint:
     name: Gauntlet ESLint

.github/workflows/lint.yml

@@ -7,6 +7,9 @@ on:
       - main
   pull_request:
 
+permissions:
+  contents: read
+
 jobs:
   lint_format_check:
     name: Format Check

.github/workflows/monitoring-build-push-ecr.yml

@@ -8,6 +8,9 @@ on:
       - monitoring/**
       - relayer/**
 
+permissions:
+  contents: read
+
 jobs:
   build-and-publish-monitoring:
     runs-on: ubuntu-latest