diff --git a/.forgejo/workflows/benchmark-scheduled.yml b/.forgejo/workflows/benchmark-scheduled.yml
index 980823508..04f7de49f 100644
--- a/.forgejo/workflows/benchmark-scheduled.yml
+++ b/.forgejo/workflows/benchmark-scheduled.yml
@@ -15,6 +15,9 @@ on:
                 required: false
                 default: "false"
 
+vars:
+    docker_prefix: "http://harbor.cleverthis.com/docker/"
+
 env:
     UV_VERSION: "0.8.0"
     PYTHON_VERSION: "3.13"
@@ -26,7 +29,7 @@ jobs:
         runs-on: docker
         timeout-minutes: 120
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install system dependencies
               run: |
@@ -111,7 +114,7 @@ jobs:
         runs-on: docker
         timeout-minutes: 180
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install system dependencies
               run: |
diff --git a/.forgejo/workflows/ci.yml b/.forgejo/workflows/ci.yml
index 9cb456745..5b04bd9c6 100644
--- a/.forgejo/workflows/ci.yml
+++ b/.forgejo/workflows/ci.yml
@@ -6,6 +6,9 @@ on:
     pull_request:
         branches: [master, develop*]
 
+vars:
+    docker_prefix: "http://harbor.cleverthis.com/docker/"
+
 env:
     UV_VERSION: "0.8.0"
     PYTHON_VERSION: "3.13"
@@ -15,7 +18,7 @@ jobs:
     lint:
         runs-on: docker
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install Node.js (required by actions/checkout)
               run: |
@@ -59,7 +62,7 @@ jobs:
     typecheck:
         runs-on: docker
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install Node.js (required by actions/checkout)
               run: |
@@ -97,7 +100,7 @@ jobs:
     security:
         runs-on: docker
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install Node.js (required by actions/checkout)
               run: |
@@ -141,7 +144,7 @@ jobs:
     quality:
         runs-on: docker
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install Node.js (required by actions/checkout)
               run: |
@@ -179,7 +182,7 @@ jobs:
     unit_tests:
         runs-on: docker
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install system dependencies (nodejs for checkout, git for merge tests, curl/tar for Helm)
               run: |
@@ -230,7 +233,7 @@ jobs:
     integration_tests:
         runs-on: docker
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install system dependencies (nodejs for checkout, git for integration tests, curl/tar for Helm)
               run: |
@@ -289,7 +292,7 @@ jobs:
         runs-on: docker
         timeout-minutes: 45
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install system dependencies (nodejs for checkout, git for E2E tests)
               run: |
@@ -334,7 +337,7 @@ jobs:
     coverage:
         runs-on: docker
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         needs: [lint, typecheck, security, quality]
         steps:
             - name: Install system dependencies (nodejs for checkout, git for merge tests)
@@ -409,7 +412,7 @@ jobs:
     build:
         runs-on: docker
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install Node.js (required by actions/checkout)
               run: |
@@ -439,7 +442,7 @@ jobs:
         needs: [lint, typecheck, security, quality, unit_tests]
         runs-on: docker
         container:
-            image: docker:dind
+            image: ${{vars.docker_prefix}}docker:dind
             options: --privileged
         steps:
             - name: Start Docker daemon and install dependencies
@@ -465,7 +468,7 @@ jobs:
     helm:
         runs-on: docker
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install system dependencies (nodejs for checkout, curl for Helm and kubeconform)
               run: |
@@ -530,7 +533,7 @@ jobs:
         # config (name/email) was set — both are required for any push operation.
         runs-on: docker
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install system dependencies (nodejs for checkout, git for push validation)
               run: |
@@ -606,7 +609,7 @@ jobs:
         needs: [lint, typecheck, security, quality, unit_tests, integration_tests, e2e_tests, coverage, build, docker, helm, push-validation]
         runs-on: docker
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Check required job results
               run: |
diff --git a/.forgejo/workflows/master.yml b/.forgejo/workflows/master.yml
index 679165383..6b291c304 100644
--- a/.forgejo/workflows/master.yml
+++ b/.forgejo/workflows/master.yml
@@ -6,6 +6,9 @@ on:
     pull_request:
         branches: [master, develop]
 
+vars:
+    docker_prefix: "http://harbor.cleverthis.com/docker/"
+
 env:
     UV_VERSION: "0.8.0"
     PYTHON_VERSION: "3.13"
@@ -16,7 +19,7 @@ jobs:
         if: forgejo.event_name == 'pull_request'
         runs-on: docker-benchmark
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
 
         steps:
             - name: Install system dependencies (nodejs for checkout, git for merge tests)
@@ -72,7 +75,7 @@ jobs:
     benchmark-publish:
         if: forgejo.event_name == 'push'
         runs-on: docker-benchmark
-        container: python:3.13-slim
+        container: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install system dependencies (nodejs for checkout, git for merge tests)
               run: |
diff --git a/.forgejo/workflows/nightly-quality.yml b/.forgejo/workflows/nightly-quality.yml
index 372c6dd9a..a1fc0a830 100644
--- a/.forgejo/workflows/nightly-quality.yml
+++ b/.forgejo/workflows/nightly-quality.yml
@@ -7,6 +7,9 @@ on:
   workflow_dispatch:
     # Allow manual trigger for testing
 
+vars:
+  docker_prefix: "http://harbor.cleverthis.com/docker/"
+
 env:
   UV_VERSION: "0.8.0"
   PYTHON_VERSION: "3.13"
@@ -16,7 +19,7 @@ jobs:
   full-quality-suite:
     runs-on: docker
     container:
-      image: python:3.13-slim
+      image: ${{vars.docker_prefix}}python:3.13-slim
     steps:
       - name: Install system dependencies (git for merge tests)
         run: |
diff --git a/.forgejo/workflows/release.yml b/.forgejo/workflows/release.yml
index ad817e49e..fef31e6bb 100644
--- a/.forgejo/workflows/release.yml
+++ b/.forgejo/workflows/release.yml
@@ -5,6 +5,9 @@ on:
         tags:
             - "v*"
 
+vars:
+    docker_prefix: "http://harbor.cleverthis.com/docker/"
+
 env:
     UV_VERSION: "0.8.0"
     PYTHON_VERSION: "3.13"
@@ -14,7 +17,7 @@ jobs:
     build-wheel:
         runs-on: docker
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         steps:
             - name: Install Node.js (required by actions/checkout)
               run: |
@@ -42,7 +45,7 @@ jobs:
     build-docker:
         runs-on: docker
         container:
-            image: docker:dind
+            image: ${{vars.docker_prefix}}docker:dind
             options: --privileged
         needs: [build-wheel]
         steps:
@@ -85,7 +88,7 @@ jobs:
     create-release:
         runs-on: docker
         container:
-            image: python:3.13-slim
+            image: ${{vars.docker_prefix}}python:3.13-slim
         needs: [build-wheel, build-docker]
         steps:
             - name: Install system dependencies