diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index 7bb8b5a..9e32d15 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-License-Identifier: PMPL-1.0
 name: CodeQL Security Analysis
 
 on:
@@ -9,6 +9,14 @@ on:
   schedule:
     - cron: '0 6 * * 1'
 
+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR
+# updates do not pile up queued runs against the shared account-wide
+# Actions concurrency pool. Applied only to read-only check workflows
+# (no publish/mutation), so cancelling a superseded run is always safe.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 permissions:
   contents: read
 
@@ -30,12 +38,12 @@ jobs:
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@b1bff81932f5cdfc8695c7752dcee935dcd061c8 # v3.28.1
+        uses: github/codeql-action/init@c6f931105cb2c34c8f901cc885ba1e2e259cf745 # v3
         with:
           languages: ${{ matrix.language }}
           build-mode: ${{ matrix.build-mode }}
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@b1bff81932f5cdfc8695c7752dcee935dcd061c8 # v3.28.1
+        uses: github/codeql-action/analyze@c6f931105cb2c34c8f901cc885ba1e2e259cf745 # v3
         with:
           category: "/language:${{ matrix.language }}"
diff --git a/.github/workflows/governance.yml b/.github/workflows/governance.yml
index 76bd1a0..4bb50e9 100644
--- a/.github/workflows/governance.yml
+++ b/.github/workflows/governance.yml
@@ -18,6 +18,14 @@ on:
   pull_request:
   workflow_dispatch:
 
+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR
+# updates do not pile up queued runs against the shared account-wide
+# Actions concurrency pool. Applied only to read-only check workflows
+# (no publish/mutation), so cancelling a superseded run is always safe.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 permissions:
   contents: read
 
diff --git a/.github/workflows/scorecard-enforcer.yml b/.github/workflows/scorecard-enforcer.yml
index 2bcc6b6..04206c0 100644
--- a/.github/workflows/scorecard-enforcer.yml
+++ b/.github/workflows/scorecard-enforcer.yml
@@ -9,6 +9,14 @@ on:
     - cron: '0 6 * * 1'  # Weekly on Monday
   workflow_dispatch:
 
+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR
+# updates do not pile up queued runs against the shared account-wide
+# Actions concurrency pool. Applied only to read-only check workflows
+# (no publish/mutation), so cancelling a superseded run is always safe.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 permissions:
   contents: read
 
@@ -19,7 +27,7 @@ jobs:
       security-events: write
       id-token: write  # For OIDC
     steps:
-      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v4
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           persist-credentials: false
 
@@ -31,7 +39,7 @@ jobs:
           publish_results: true
 
       - name: Upload SARIF
-        uses: github/codeql-action/upload-sarif@b1bff81932f5cdfc8695c7752dcee935dcd061c8 # v3
+        uses: github/codeql-action/upload-sarif@c6f931105cb2c34c8f901cc885ba1e2e259cf745 # v4
         with:
           sarif_file: results.sarif
 
@@ -54,7 +62,7 @@ jobs:
   check-critical:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v4
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Check SECURITY.md exists
         run: |
diff --git a/.github/workflows/scorecard.yml b/.github/workflows/scorecard.yml
index ac6c208..29853b2 100644
--- a/.github/workflows/scorecard.yml
+++ b/.github/workflows/scorecard.yml
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-License-Identifier: PMPL-1.0
 name: OSSF Scorecard
 on:
   push:
@@ -7,6 +7,14 @@ on:
     - cron: '0 4 * * *'
   workflow_dispatch:
 
+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR
+# updates do not pile up queued runs against the shared account-wide
+# Actions concurrency pool. Applied only to read-only check workflows
+# (no publish/mutation), so cancelling a superseded run is always safe.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 permissions:
   contents: read
 
@@ -28,6 +36,6 @@ jobs:
           results_format: sarif
 
       - name: Upload results
-        uses: github/codeql-action/upload-sarif@b1bff81932f5cdfc8695c7752dcee935dcd061c8 # v3.31.8
+        uses: github/codeql-action/upload-sarif@c6f931105cb2c34c8f901cc885ba1e2e259cf745 # v3.31.8
         with:
           sarif_file: results.sarif
diff --git a/.github/workflows/secret-scanner.yml b/.github/workflows/secret-scanner.yml
index fa158c6..8801d53 100644
--- a/.github/workflows/secret-scanner.yml
+++ b/.github/workflows/secret-scanner.yml
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-License-Identifier: PMPL-1.0
 # Prevention workflow - scans for hardcoded secrets before they reach main
 name: Secret Scanner
 
@@ -7,6 +7,14 @@ on:
   push:
     branches: [main]
 
+# Estate guardrail: cancel superseded runs so re-pushes / rebased PR
+# updates do not pile up queued runs against the shared account-wide
+# Actions concurrency pool. Applied only to read-only check workflows
+# (no publish/mutation), so cancelling a superseded run is always safe.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 permissions:
   contents: read
 
@@ -19,7 +27,7 @@ jobs:
           fetch-depth: 0  # Full history for scanning
 
       - name: TruffleHog Secret Scan
-        uses: trufflesecurity/trufflehog@8a8ef8526528d8a4ff3e2c90be08e25ef8efbd9b # v3
+        uses: trufflesecurity/trufflehog@6c05c4a00b91aa542267d8e32a8254774799d68d # v3
         with:
           # The v3 action injects --fail automatically on pull_request events.
           # Passing --fail here triggers "flag 'fail' cannot be repeated".
@@ -70,4 +78,4 @@ jobs:
           if [ $found -eq 1 ]; then
             echo "::error::Potential hardcoded secrets detected. Use environment variables instead."
             exit 1
-          fi
\ No newline at end of file
+          fi