diff --git a/.github/workflows/brand-headers.yml b/.github/workflows/brand-headers.yml
index 522e7c2a0..8f8661a01 100644
--- a/.github/workflows/brand-headers.yml
+++ b/.github/workflows/brand-headers.yml
@@ -28,7 +28,7 @@ jobs:
     
     steps:
     - name: 📥 Checkout Repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       
     - name: 🟢 Setup Node.js
       uses: actions/setup-node@v4
diff --git a/.github/workflows/ci-unified.yml b/.github/workflows/ci-unified.yml
index 8580f7907..81c8c4624 100644
--- a/.github/workflows/ci-unified.yml
+++ b/.github/workflows/ci-unified.yml
@@ -48,7 +48,7 @@ jobs:
       should_deploy: ${{ steps.check.outputs.should_deploy }}
       deploy_target: ${{ steps.check.outputs.deploy_target }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - id: check
         run: |
           if [[ "${{ github.ref }}" == "refs/heads/production" && "${{ github.event_name }}" == "push" ]]; then
@@ -72,7 +72,7 @@ jobs:
     name: "Stage 1: Security Gates"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
@@ -118,7 +118,7 @@ jobs:
     name: "Stage 2: Code Quality"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.NODE_VERSION }}
@@ -139,7 +139,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: [quality]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.NODE_VERSION }}
@@ -164,7 +164,7 @@ jobs:
     name: "Stage 3b: Python Tests"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
@@ -180,7 +180,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: [quality]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.NODE_VERSION }}
@@ -200,7 +200,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: [test-node, security, validate]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.NODE_VERSION }}
@@ -223,7 +223,7 @@ jobs:
       contents: read
       id-token: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Authenticate to Google Cloud
         uses: google-github-actions/auth@v3
         with:
@@ -261,7 +261,7 @@ jobs:
     needs: [build, preflight]
     if: needs.preflight.outputs.should_deploy == 'true'
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.NODE_VERSION }}
@@ -287,7 +287,7 @@ jobs:
     needs: [deploy-cloud-run]
     if: always() && needs.deploy-cloud-run.result == 'success'
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: ${{ env.NODE_VERSION }}
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index fada83399..92768fc68 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,7 +17,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
diff --git a/.github/workflows/clean-build-ci.yml b/.github/workflows/clean-build-ci.yml
index e4b3a6146..7ee2d63fc 100644
--- a/.github/workflows/clean-build-ci.yml
+++ b/.github/workflows/clean-build-ci.yml
@@ -69,7 +69,7 @@ jobs:
       changed_files: ${{ steps.changes.outputs.all_changed_files }}
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
@@ -116,7 +116,7 @@ jobs:
     timeout-minutes: 15
     steps:
       - name: Checkout code (fresh clone)
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           # Clean build: no cache, fresh clone
           clean: true
@@ -239,7 +239,7 @@ jobs:
     timeout-minutes: 10
     steps:
       - name: Checkout code (fresh clone)
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           clean: true
 
@@ -280,7 +280,7 @@ jobs:
     timeout-minutes: 10
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Run npm audit
         run: |
@@ -334,7 +334,7 @@ jobs:
         test-type: [unit, integration, e2e]
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
@@ -405,7 +405,7 @@ jobs:
     timeout-minutes: 5
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
@@ -586,7 +586,7 @@ jobs:
     timeout-minutes: 5
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
@@ -617,7 +617,7 @@ jobs:
     timeout-minutes: 15
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
@@ -731,7 +731,7 @@ jobs:
 # - Add performance benchmarks
 # - Add deployment stages
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 100  # Fetch history for performance analysis
 
diff --git a/.github/workflows/clean-build.yml b/.github/workflows/clean-build.yml
index 58b437fbf..cd7fcbe72 100644
--- a/.github/workflows/clean-build.yml
+++ b/.github/workflows/clean-build.yml
@@ -35,7 +35,7 @@ jobs:
       changed_services: ${{ steps.changes.outputs.services }}
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           # Full clone for clean build verification
           fetch-depth: 0
@@ -93,7 +93,7 @@ jobs:
     timeout-minutes: 30
     steps:
       - name: Checkout code (fresh)
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           clean: true  # Remove any existing files
           
@@ -260,7 +260,7 @@ jobs:
         working-directory: frontend
     steps:
       - name: Checkout code (fresh)
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           clean: true
           
@@ -310,7 +310,7 @@ jobs:
         working-directory: backend/python_worker
     steps:
       - name: Checkout code (fresh)
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           clean: true
           
@@ -382,7 +382,7 @@ jobs:
           - 6379:6379
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         
       - name: Download manager artifacts
         uses: actions/download-artifact@v4
@@ -426,7 +426,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         
       - name: Run Trivy vulnerability scanner
         uses: aquasecurity/trivy-action@master
diff --git a/.github/workflows/deploy-workers.yml b/.github/workflows/deploy-workers.yml
index ac085e75c..555dce220 100644
--- a/.github/workflows/deploy-workers.yml
+++ b/.github/workflows/deploy-workers.yml
@@ -14,7 +14,7 @@ jobs:
     
     steps:
     - name: Checkout
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       
     - name: Setup Node
       uses: actions/setup-node@v4
diff --git a/.github/workflows/electron-build.yml b/.github/workflows/electron-build.yml
index 6d8630792..5fc0a8408 100644
--- a/.github/workflows/electron-build.yml
+++ b/.github/workflows/electron-build.yml
@@ -15,7 +15,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
@@ -66,7 +66,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
@@ -115,7 +115,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
@@ -171,7 +171,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 15
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
@@ -216,7 +216,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
diff --git a/.github/workflows/env-validator.yml b/.github/workflows/env-validator.yml
index 8685b2904..88490a2ad 100644
--- a/.github/workflows/env-validator.yml
+++ b/.github/workflows/env-validator.yml
@@ -37,7 +37,7 @@ jobs:
     # ── Node 20 LTS ──────────────────────────────────────────────────────────
     steps:
       - name: "Checkout repository"
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: "Setup Node.js 20"
         uses: actions/setup-node@v4
diff --git a/.github/workflows/file_maintenance.yml b/.github/workflows/file_maintenance.yml
index 254121e40..77fe06929 100644
--- a/.github/workflows/file_maintenance.yml
+++ b/.github/workflows/file_maintenance.yml
@@ -25,7 +25,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         
       - name: Run pre-scan check
         run: |
@@ -77,7 +77,7 @@ jobs:
       should_scan: ${{ steps.check.outputs.should_scan }}
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
@@ -103,7 +103,7 @@ jobs:
     timeout-minutes: ${{ env.SCAN_TIMEOUT }}
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           clean: true
 
diff --git a/.github/workflows/hcfp-clean-build.yml b/.github/workflows/hcfp-clean-build.yml
index ec3499730..2f9a556ad 100644
--- a/.github/workflows/hcfp-clean-build.yml
+++ b/.github/workflows/hcfp-clean-build.yml
@@ -32,7 +32,7 @@ jobs:
     
     steps:
       - name: 📥 Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0  # Full history for proper builds
       
@@ -93,7 +93,7 @@ jobs:
     
     steps:
       - name: 📥 Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       
       - name: 🧹 Clean Workspace (No Artifacts)
         run: |
@@ -216,7 +216,7 @@ jobs:
     
     steps:
       - name: 📥 Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       
       - name: 🧹 Clean Test Environment
         run: |
@@ -261,7 +261,7 @@ jobs:
     
     steps:
       - name: 📥 Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       
       - name: 🔍 Secret Detection
         uses: trufflesecurity/trufflehog@main
@@ -437,7 +437,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: 📥 Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       
       - name: 🔍 Check for api.headysystems.com in Production Code
         run: |
diff --git a/.github/workflows/hcfp-production-clean-build.yml b/.github/workflows/hcfp-production-clean-build.yml
index 2a9b7968b..bc59b5788 100644
--- a/.github/workflows/hcfp-production-clean-build.yml
+++ b/.github/workflows/hcfp-production-clean-build.yml
@@ -20,7 +20,7 @@ jobs:
     outputs:
       should_proceed: ${{ steps.validate.outputs.proceed }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       
       - name: Validate no api.headysystems.com in production configs
         id: validate
@@ -50,7 +50,7 @@ jobs:
     if: needs.preflight.outputs.should_proceed == 'true'
     
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           clean: true
       
@@ -122,7 +122,7 @@ jobs:
     if: needs.preflight.outputs.should_proceed == 'true'
     
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           clean: true
       
@@ -156,7 +156,7 @@ jobs:
     needs: [build-node, build-python]
     
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       
       - name: Run npm audit
         run: |
@@ -201,7 +201,7 @@ jobs:
           - 6379:6379
     
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       
       - uses: actions/setup-node@v4
         with:
@@ -280,7 +280,7 @@ jobs:
     if: needs.preflight.outputs.should_proceed == 'true'
     
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       
       - name: Setup Node.js
         uses: actions/setup-node@v4
@@ -327,7 +327,7 @@ jobs:
     if: github.ref == 'refs/heads/main' && needs.build-complete.result == 'success'
     
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       
       - name: Setup Python for YAML validation
         uses: actions/setup-python@v5
@@ -501,7 +501,7 @@ jobs:
     if: needs.preflight.outputs.should_proceed == 'true'
     
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       
       - name: Setup Node.js
         uses: actions/setup-node@v4
diff --git a/.github/workflows/naming-checks.yml b/.github/workflows/naming-checks.yml
index 3fa9387e4..a454196dd 100644
--- a/.github/workflows/naming-checks.yml
+++ b/.github/workflows/naming-checks.yml
@@ -26,7 +26,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         
       - name: Check for banned patterns
         run: |
diff --git a/.github/workflows/naming-compliance.yml b/.github/workflows/naming-compliance.yml
index be99c5b40..17cc3d907 100644
--- a/.github/workflows/naming-compliance.yml
+++ b/.github/workflows/naming-compliance.yml
@@ -26,7 +26,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
 
     - name: Run naming audit
       run: |
diff --git a/.github/workflows/sync-autocontext.yml b/.github/workflows/sync-autocontext.yml
index 6a5323b33..ed5d7caea 100644
--- a/.github/workflows/sync-autocontext.yml
+++ b/.github/workflows/sync-autocontext.yml
@@ -25,7 +25,7 @@ jobs:
 
     steps:
     - name: Checkout Source
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         fetch-depth: 1