ci: bump GitHub Actions to Node 24 majors

Clears the Node 20 deprecation warnings (forced to Node 24 by GitHub on
2026-06-16). Verified each target major defaults to runs.using: node24:

- actions/checkout v4 -> v5
- actions/setup-python v5 -> v6
- actions/upload-artifact v4 -> v6 (v5 still defaults to Node 20)
- actions/github-script v7 -> v8 (v9 drops require('@actions/github'); our
  scripts use only injected github/context, but v8 is the minimal Node 24 bump)
- actions/configure-pages v4 -> v6
- actions/upload-pages-artifact v4 -> v5
- actions/deploy-pages v4 -> v5

No functional changes to any workflow.

Author: Paul Duvall

.github/workflows/claude-code-review.yml

@@ -27,7 +27,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           fetch-depth: 1
 

.github/workflows/claude.yml

@@ -25,7 +25,7 @@ jobs:
       id-token: write
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           fetch-depth: 1
 

.github/workflows/deploy-pages.yml

@@ -19,13 +19,13 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Setup Pages
-        uses: actions/configure-pages@v4
+        uses: actions/configure-pages@v6
 
       - name: Upload artifact
-        uses: actions/upload-pages-artifact@v4
+        uses: actions/upload-pages-artifact@v5
         with:
           path: '.'
 
@@ -38,4 +38,4 @@ jobs:
     steps:
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v4
+        uses: actions/deploy-pages@v5

.github/workflows/pattern-validation.yml

@@ -15,10 +15,10 @@ jobs:
     name: Pattern Specification Compliance
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
 
     - name: Set up Python 3.11
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: '3.11'
 
@@ -33,7 +33,7 @@ jobs:
         python3 -m pytest test_pattern_compliance.py -v --tb=short
     
     - name: Upload compliance test results
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       if: always()
       with:
         name: pattern-compliance-results
@@ -44,10 +44,10 @@ jobs:
     name: README Accuracy & Consistency
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
 
     - name: Set up Python 3.11
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: '3.11'
 
@@ -78,7 +78,7 @@ jobs:
         python3 -m pytest test_readme_accuracy.py -v --tb=short
 
     - name: Upload accuracy test results
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       if: always()
       with:
         name: readme-accuracy-results
@@ -89,10 +89,10 @@ jobs:
     name: Hyperlink Integrity
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
 
     - name: Set up Python 3.11
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: '3.11'
 
@@ -113,7 +113,7 @@ jobs:
       continue-on-error: true  # External links may be temporarily unavailable
 
     - name: Upload link validation results
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       if: always()
       with:
         name: link-validation-results
@@ -124,10 +124,10 @@ jobs:
     name: Example Code Validation
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
 
     - name: Set up Python 3.11
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: '3.11'
 
@@ -147,7 +147,7 @@ jobs:
         python3 -m pytest test_examples.py -v --tb=short
     
     - name: Upload example validation results
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       if: always()
       with:
         name: example-validation-results
@@ -158,10 +158,10 @@ jobs:
     name: Pattern Dependencies
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
 
     - name: Set up Python 3.11
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: '3.11'
 
@@ -176,7 +176,7 @@ jobs:
         python3 -m pytest test_dependencies.py -v --tb=short
 
     - name: Upload dependency validation results
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       if: always()
       with:
         name: dependency-validation-results
@@ -187,10 +187,10 @@ jobs:
     name: Diagram Accuracy
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
 
     - name: Set up Python 3.11
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: '3.11'
 
@@ -205,7 +205,7 @@ jobs:
         python3 -m pytest test_diagram.py -v --tb=short
 
     - name: Upload diagram validation results
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       if: always()
       with:
         name: diagram-validation-results
@@ -216,10 +216,10 @@ jobs:
     name: YAML-README Sync
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
 
     - name: Set up Python 3.11
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: '3.11'
 
@@ -234,7 +234,7 @@ jobs:
         python3 -m pytest test_yaml_readme_sync.py -v --tb=short
 
     - name: Upload sync test results
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       if: always()
       with:
         name: yaml-readme-sync-results
@@ -247,10 +247,10 @@ jobs:
     if: always()
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
 
     - name: Set up Python 3.11
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: '3.11'
 
@@ -292,7 +292,7 @@ jobs:
       run: exit 1
 
     - name: Upload comprehensive test report
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       if: always()
       with:
         name: comprehensive-test-report
@@ -309,10 +309,10 @@ jobs:
     if: github.event_name == 'pull_request'
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
 
     - name: Set up Python 3.11
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: '3.11'
 
@@ -346,7 +346,7 @@ jobs:
 
     steps:
     - name: Create Issue on Failure (skip if duplicate)
-      uses: actions/github-script@v7
+      uses: actions/github-script@v8
       with:
         script: |
           const { data: existing } = await github.rest.issues.listForRepo({
@@ -407,7 +407,7 @@ jobs:
 
     steps:
     - name: Close pattern-validation issues
-      uses: actions/github-script@v7
+      uses: actions/github-script@v8
       with:
         script: |
           const { data: issues } = await github.rest.issues.listForRepo({