fix: Pin all GitHub Actions to full commit SHAs (13 files)

Security compliance - SHA pinning for all actions.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/self-healing.yml

@@ -15,7 +15,7 @@ jobs:
     
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
       
       - name: Check Health
         id: health
@@ -48,7 +48,7 @@ jobs:
       
       - name: Create Issue on Failure
         if: failure()
-        uses: actions/github-script@v7
+        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea
         with:
           script: |
             github.rest.issues.create({
@@ -65,11 +65,11 @@ jobs:
     
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
       
       - name: Setup Node
         if: hashFiles('package.json') != ''
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@39370e3970a6d050c480ffad4ff0ed4d3fdee5af
         with:
           node-version: '20'