fix: downgrade actions/checkout from v6.0.1 to v4.2.2

Checkout v6.0.1 was released yesterday (Dec 2, 2025) and is causing CI
failures across all workflows. The v6 release requires minimum GitHub
Actions Runner v2.329.0 for Docker container scenarios and likely has
edge cases causing failures.

Downgrading to v4.2.2 (stable release from Oct 2024) to restore CI
stability. Can re-evaluate v6 after it matures.

Affects 16 checkout action references across 12 workflow files:
- quality-checks.yml
- waf-integration.yml
- docker-publish.yml
- codecov-upload.yml
- codeql.yml
- benchmark.yml
- docs.yml
- release-goreleaser.yml
- auto-versioning.yml
- docker-lint.yml
- auto-changelog.yml
- renovate.yml

.github/workflows/auto-changelog.yml

@@ -10,7 +10,7 @@ jobs:
   update-draft:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Draft Release
         uses: release-drafter/release-drafter@b1476f6e6eb133afa41ed8589daba6dc69b4d3f5 # v6
         env:

.github/workflows/auto-versioning.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           fetch-depth: 0
 

.github/workflows/benchmark.yml

@@ -24,7 +24,7 @@ jobs:
     name: Performance Regression Check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Set up Go
         uses: actions/setup-go@4dc6199c7b1a012772edbd06daecab0f50c9053c # v6

.github/workflows/codecov-upload.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           fetch-depth: 0
 
@@ -47,7 +47,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           fetch-depth: 0
 

.github/workflows/codeql.yml

@@ -31,7 +31,7 @@ jobs:
         language: [ 'go', 'javascript-typescript' ]
     steps:
       - name: Checkout repository
-        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Initialize CodeQL
         uses: github/codeql-action/init@fe4161a26a8629af62121b670040955b330f9af2 # v4

.github/workflows/docker-lint.yml

@@ -14,7 +14,7 @@ jobs:
   hadolint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Run Hadolint
         uses: hadolint/hadolint-action@2332a7b74a6de0dda2e2221d575162eba76ba5e5 # v3.3.0

.github/workflows/docker-publish.yml

@@ -34,7 +34,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Normalize image name
         run: |
@@ -181,7 +181,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Normalize image name
         run: |
@@ -258,7 +258,7 @@ jobs:
     if: github.event_name == 'pull_request'
     steps:
       - name: Checkout repository
-        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Build image locally for PR
         run: |

.github/workflows/docs.yml

@@ -29,7 +29,7 @@ jobs:
     steps:
       # Step 1: Get the code
       - name: 📥 Checkout code
-        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       # Step 2: Set up Node.js (for building any JS-based doc tools)
       - name: 🔧 Set up Node.js

.github/workflows/quality-checks.yml

@@ -11,7 +11,7 @@ jobs:
     name: Backend (Go)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Set up Go
         uses: actions/setup-go@4dc6199c7b1a012772edbd06daecab0f50c9053c # v6.1.0
@@ -62,7 +62,7 @@ jobs:
     name: Frontend (React)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Set up Node.js
         uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # v6.1.0

.github/workflows/release-goreleaser.yml

@@ -19,7 +19,7 @@ jobs:
       CHARON_TOKEN: ${{ secrets.CHARON_TOKEN }}
     steps:
       - name: Checkout
-        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           fetch-depth: 0
 

.github/workflows/renovate.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           fetch-depth: 1
       - name: Choose Renovate Token

.github/workflows/waf-integration.yml

@@ -27,7 +27,7 @@ jobs:
     timeout-minutes: 15
 
     steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3.11.1