ci: pin third-party actions to commit SHAs and add least-privilege permissions (REQ-1.4.10)

- Pin actions/checkout, setup-python, codeql-action init/autobuild/analyze,
  upload-pages-artifact, deploy-pages, amannn/action-semantic-pull-request, and
  actions/stale to immutable commit SHAs across ci.yml, codeql.yml, pages.yml,
  pr-lint.yml, stale.yml
- Tags resolved live via gh api (2026-07-07) since files were already bumped past the
  phase-31-01 baseline (checkout v7, setup-python v6, codeql-action v4,
  upload-pages-artifact v5, deploy-pages v5, action-semantic-pull-request v6, stale v10)
- codeql.yml, pr-lint.yml, and stale.yml already carry permissions: blocks (added ahead
  of this plan); not modified here — only uses: lines changed
- contract-registry-live.yml already SHA-pinned; left untouched

Author: Aitomates

.github/workflows/ci.yml

@@ -24,10 +24,10 @@ jobs:
         python-version: ['3.12']
 
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
 
       - name: Set up Python
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1 # v6
         with:
           python-version: ${{ matrix.python-version }}
           cache: pip

.github/workflows/codeql.yml

@@ -19,12 +19,12 @@ jobs:
         language: [ 'javascript', 'python' ]
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v7
+      uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v4
+      uses: github/codeql-action/init@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4
       with:
         languages: ${{ matrix.language }}
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v4
+      uses: github/codeql-action/autobuild@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v4
+      uses: github/codeql-action/analyze@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4

.github/workflows/pages.yml

@@ -14,13 +14,13 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 15
     steps:
-      - uses: actions/checkout@v7
-      - uses: actions/setup-python@v6
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+      - uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1 # v6
         with:
           python-version: 3.x
       - run: pip install mkdocs-material
       - run: mkdocs build
-      - uses: actions/upload-pages-artifact@v5
+      - uses: actions/upload-pages-artifact@fc324d3547104276b827a68afc52ff2a11cc49c9 # v5
         with:
           path: ./site
   deploy:
@@ -36,4 +36,4 @@ jobs:
     steps:
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v5
+        uses: actions/deploy-pages@cd2ce8fcbc39b97be8ca5fce6e763baed58fa128 # v5

.github/workflows/pr-lint.yml

@@ -13,6 +13,6 @@ jobs:
     permissions:
       pull-requests: read
     steps:
-      - uses: amannn/action-semantic-pull-request@v6
+      - uses: amannn/action-semantic-pull-request@48f256284bd46cdaab1048c3721360e808335d50 # v6
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/stale.yml

@@ -11,7 +11,7 @@ jobs:
       issues: write
       pull-requests: write
     steps:
-      - uses: actions/stale@v10
+      - uses: actions/stale@eb5cf3af3ac0a1aa4c9c45633dd1ae542a27a899 # v10
         with:
           days-before-stale: 60
           days-before-close: 7