diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d89b5467..5a53c581 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,6 +8,11 @@ on:
 permissions:
   contents: read
 
+# Keep every non-PR run; only superseded PR validation is cancelled.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
 jobs:
   test:
     name: test + lint (full offline stack)
@@ -227,6 +232,9 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
           python-version: ${{ matrix.python-version }}
       - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
@@ -265,9 +273,15 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
           python-version: "3.11"
       - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
+          cache: npm
+          cache-dependency-path: |
+            package-lock.json
           node-version: "24"
       - name: Install dashboard and browser test dependencies
         run: |
@@ -394,6 +408,9 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
           python-version: "3.11"
       - name: Install pinned build and audit tooling
         run: >-
@@ -430,6 +447,10 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            .github/release-constraints.txt
           python-version: "3.11"
       - name: Build the candidate wheel
         run: |
@@ -475,6 +496,7 @@ jobs:
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
         with:
           name: candidate-journey-${{ matrix.os }}-${{ matrix.profile }}
+          retention-days: 14
           path: |
             ${{ runner.temp }}/installed-candidate/journey.json
             ${{ runner.temp }}/installed-candidate/environment.lock
diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index ef36cd5b..ebd6a714 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -14,10 +14,16 @@ permissions:
   packages: read
   security-events: write
 
+# Keep every non-PR run; only superseded PR validation is cancelled.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
 jobs:
   analyze:
     name: Analyze ${{ matrix.language }}
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     # Pull-request analyses otherwise use diff-informed queries, whose SARIF
     # intentionally omits findings outside changed lines. The release gate
     # must inspect complete raw SARIF on both pull requests and pushes.
diff --git a/.github/workflows/export-offline-evidence.yml b/.github/workflows/export-offline-evidence.yml
index 206ba38f..fa9b6dca 100644
--- a/.github/workflows/export-offline-evidence.yml
+++ b/.github/workflows/export-offline-evidence.yml
@@ -17,9 +17,15 @@ on:
       - "scripts/export_offline_evidence.py"
 permissions:
   contents: read
+# Keep every non-PR run; only superseded PR validation is cancelled.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
 jobs:
   export:
     runs-on: ubuntu-latest
+    timeout-minutes: 10
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
         with:
diff --git a/.github/workflows/release-pi.yml b/.github/workflows/release-pi.yml
index b61424c3..94cc6b3b 100644
--- a/.github/workflows/release-pi.yml
+++ b/.github/workflows/release-pi.yml
@@ -13,12 +13,16 @@ jobs:
   build:
     name: Verify and pack Pi extension
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
         with:
           fetch-depth: 0
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
           python-version: "3.11"
       - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
@@ -76,6 +80,7 @@ jobs:
     # protected pi-v* tag and npm Trusted Publishing configured for this workflow.
     if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/pi-v')
     runs-on: ubuntu-latest
+    timeout-minutes: 15
     permissions:
       contents: read
       id-token: write
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index d4225044..ae61d273 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -34,6 +34,7 @@ jobs:
   build:
     name: Build distributions
     runs-on: ubuntu-latest
+    timeout-minutes: 60
     if: >-
       github.event_name == 'push' ||
       inputs.release_tag == ''
@@ -50,6 +51,10 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            .github/release-constraints.txt
           python-version: "3.11"
 
       - name: Install release gate and the production dependency set (without SQLCipher)
@@ -167,6 +172,7 @@ jobs:
   reproducibility-build:
     name: Independent distribution builder ${{ matrix.builder }}
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     if: >-
       github.event_name == 'push' ||
       inputs.release_tag == ''
@@ -184,6 +190,10 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            .github/release-constraints.txt
           python-version: "3.11"
       - name: Build in isolated pinned environment
         shell: bash
@@ -207,6 +217,7 @@ jobs:
     name: Compare independent distribution builders
     needs: [build, reproducibility-build]
     runs-on: ubuntu-latest
+    timeout-minutes: 15
     if: >-
       github.event_name == 'push' ||
       inputs.release_tag == ''
@@ -295,6 +306,7 @@ jobs:
   python-matrix:
     name: Python ${{ matrix.python-version }} release gate
     runs-on: ubuntu-latest
+    timeout-minutes: 60
     strategy:
       fail-fast: false
       matrix:
@@ -306,6 +318,10 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            .github/release-constraints.txt
           python-version: ${{ matrix.python-version }}
       - name: Install version-appropriate gate
         shell: bash
@@ -336,6 +352,7 @@ jobs:
       github.event_name == 'push' ||
       inputs.release_tag == ''
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     steps:
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
@@ -405,6 +422,10 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            .github/release-constraints.txt
           python-version: "3.11"
       - name: Download exact release distributions
         uses: actions/download-artifact@9000827ccba6bdab643e8b6fd33ac0654aef8333 # v8
@@ -473,6 +494,7 @@ jobs:
   encryption:
     name: Encryption driver release gate (Python ${{ matrix.python-version }})
     runs-on: ubuntu-latest
+    timeout-minutes: 20
     strategy:
       fail-fast: false
       matrix:
@@ -484,6 +506,10 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            .github/release-constraints.txt
           python-version: ${{ matrix.python-version }}
       - name: Install encryption integration gate
         run: |
@@ -497,6 +523,7 @@ jobs:
   browser-accessibility:
     name: Browser accessibility release gate
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     if: >-
       github.event_name == 'push' ||
       inputs.release_tag == ''
@@ -504,9 +531,16 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            .github/release-constraints.txt
           python-version: "3.11"
       - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
+          cache: npm
+          cache-dependency-path: |
+            package-lock.json
           node-version: "24"
       - name: Install browser gate
         run: |
@@ -526,6 +560,7 @@ jobs:
   pi-extension:
     name: Pi extension release gate
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     if: >-
       github.event_name == 'push' ||
       inputs.release_tag == ''
@@ -533,6 +568,10 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            .github/release-constraints.txt
           python-version: "3.11"
       - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
@@ -556,6 +595,7 @@ jobs:
   docker-smoke:
     name: Production image release gate
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     if: >-
       github.event_name == 'push' ||
       inputs.release_tag == ''
@@ -723,6 +763,7 @@ jobs:
       github.event_name == 'push' ||
       inputs.release_tag == ''
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     permissions:
       contents: read
       security-events: write
@@ -757,6 +798,7 @@ jobs:
     needs: [build, reproducibility-check, python-matrix, artifact-core-py39, installed-artifact-platform-smoke, encryption, browser-accessibility, pi-extension, docker-smoke, code-security]
     if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
     runs-on: ubuntu-latest
+    timeout-minutes: 15
     permissions:
       contents: read
 
@@ -841,6 +883,7 @@ jobs:
     # semver tag, whose value was matched to pyproject.toml in the build job above.
     if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     permissions:
       id-token: write
       contents: read
@@ -849,6 +892,10 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            .github/release-constraints.txt
           python-version: "3.11"
       - name: Download distributions
         uses: actions/download-artifact@9000827ccba6bdab643e8b6fd33ac0654aef8333 # v8
@@ -906,6 +953,7 @@ jobs:
     environment: release-qualification
     if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     permissions:
       contents: write
 
@@ -913,6 +961,10 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            .github/release-constraints.txt
           python-version: "3.11"
       - name: Download distributions
         uses: actions/download-artifact@9000827ccba6bdab643e8b6fd33ac0654aef8333 # v8
@@ -974,6 +1026,7 @@ jobs:
       github.ref == 'refs/heads/main' &&
       inputs.release_tag != ''
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     permissions:
       actions: read
       contents: write
@@ -983,6 +1036,10 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
+          cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            .github/release-constraints.txt
           python-version: "3.11"
       - name: Enforce and record the release-specific qualification waiver
         if: inputs.waive_v176_qualification || inputs.waive_v178_qualification || inputs.waive_v179_qualification