diff --git a/.github/workflows/cancel_duplicates.yml b/.github/workflows/cancel_duplicates.yml
deleted file mode 100644
index 76525767ad0..00000000000
--- a/.github/workflows/cancel_duplicates.yml
+++ /dev/null
@@ -1,43 +0,0 @@
-name: Cancel Duplicates
-on:
-  workflow_run:
-    workflows:
-      - "Miscellaneous"
-    types:
-      - requested
-
-jobs:
-  cancel-duplicate-runs:
-    name: Cancel duplicate workflow runs
-    runs-on: ubuntu-24.04
-    permissions:
-      actions: write
-      contents: read
-    steps:
-      - name: Check number of queued tasks
-        id: check_queued
-        env:
-          GITHUB_TOKEN: ${{ github.token }}
-          GITHUB_REPO: ${{ github.repository }}
-        run: |
-          get_count() {
-            echo $(curl -s -H "Authorization: token $GITHUB_TOKEN" \
-                    "https://api.github.com/repos/$GITHUB_REPO/actions/runs?status=$1" | \
-                    jq ".total_count")
-          }
-          count=$(( `get_count queued` + `get_count in_progress` ))
-          echo "Found $count unfinished jobs."
-          echo "count=$count" >> $GITHUB_OUTPUT
-
-      - name: "Checkout ${{ github.ref }} ( ${{ github.sha }} )"
-        if: steps.check_queued.outputs.count >= 20
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
-
-      - name: Cancel duplicate workflow runs
-        if: steps.check_queued.outputs.count >= 20
-        env:
-          GITHUB_TOKEN: ${{ github.token }}
-          GITHUB_REPOSITORY: ${{ github.repository }}
-        run: |
-          pip install click requests typing_extensions python-dateutil
-          python ./scripts/cancel_github_workflows.py
diff --git a/.github/workflows/ephemeral-env-pr-close.yml b/.github/workflows/ephemeral-env-pr-close.yml
deleted file mode 100644
index b7f79c69283..00000000000
--- a/.github/workflows/ephemeral-env-pr-close.yml
+++ /dev/null
@@ -1,83 +0,0 @@
-name: Cleanup ephemeral envs (PR close) [DEPRECATED]
-
-# ⚠️  DEPRECATION NOTICE ⚠️
-# This workflow is deprecated and will be removed in a future version.
-# The new Superset Showtime workflow handles cleanup automatically.
-# See .github/workflows/showtime.yml and showtime-cleanup.yml for replacements.
-# Migration guide: https://github.com/mistercrunch/superset-showtime
-
-on:
-  pull_request_target:
-    types: [closed]
-
-jobs:
-  config:
-    runs-on: ubuntu-24.04
-    outputs:
-      has-secrets: ${{ steps.check.outputs.has-secrets }}
-    steps:
-      - name: "Check for secrets"
-        id: check
-        shell: bash
-        run: |
-          if [ -n "${AWS_ACCESS_KEY_ID}" ]; then
-            echo "has-secrets=1" >> "$GITHUB_OUTPUT"
-          fi
-
-        env:
-          AWS_ACCESS_KEY_ID: ${{ (secrets.AWS_ACCESS_KEY_ID != '' && secrets.AWS_SECRET_ACCESS_KEY != '') || '' }}
-  ephemeral-env-cleanup:
-    needs: config
-    if: needs.config.outputs.has-secrets
-    name: Cleanup ephemeral envs
-    runs-on: ubuntu-24.04
-    permissions:
-      pull-requests: write
-    steps:
-      - name: Configure AWS credentials
-        uses: aws-actions/configure-aws-credentials@8df5847569e6427dd6c4fb1cf565c83acfa8afa7 # v6
-        with:
-          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
-          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
-          aws-region: us-west-2
-
-      - name: Describe ECS service
-        id: describe-services
-        run: |
-          echo "active=$(aws ecs describe-services --cluster superset-ci --services pr-${{ github.event.number }}-service | jq '.services[] | select(.status == "ACTIVE") | any')" >> $GITHUB_OUTPUT
-
-      - name: Delete ECS service
-        if: steps.describe-services.outputs.active == 'true'
-        id: delete-service
-        run: |
-          aws ecs delete-service \
-          --cluster superset-ci \
-          --service pr-${{ github.event.number }}-service \
-          --force
-
-      - name: Login to Amazon ECR
-        if: steps.describe-services.outputs.active == 'true'
-        id: login-ecr
-        uses: aws-actions/amazon-ecr-login@fa648b43de3d4d023bcb3f89ed6940096949c419 # v2
-
-      - name: Delete ECR image tag
-        if: steps.describe-services.outputs.active == 'true'
-        id: delete-image-tag
-        run: |
-          aws ecr batch-delete-image \
-          --registry-id $(echo "${{ steps.login-ecr.outputs.registry }}" | grep -Eo "^[0-9]+") \
-          --repository-name superset-ci \
-          --image-ids imageTag=pr-${{ github.event.number }}
-
-      - name: Comment (success)
-        if: steps.describe-services.outputs.active == 'true'
-        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
-        with:
-          github-token: ${{github.token}}
-          script: |
-            github.rest.issues.createComment({
-              issue_number: ${{ github.event.number }},
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              body: '⚠️ **DEPRECATED WORKFLOW** - Ephemeral environment shutdown and build artifacts deleted. Please migrate to the new Superset Showtime system for future PRs.'
-            })
diff --git a/.github/workflows/ephemeral-env.yml b/.github/workflows/ephemeral-env.yml
deleted file mode 100644
index 8dd91b80c98..00000000000
--- a/.github/workflows/ephemeral-env.yml
+++ /dev/null
@@ -1,350 +0,0 @@
-name: Ephemeral env workflow [DEPRECATED]
-
-# ⚠️  DEPRECATION NOTICE ⚠️
-# This workflow is deprecated and will be removed in a future version.
-# Please use the new Superset Showtime workflow instead:
-# - Use label "🎪 trigger-start" instead of "testenv-up"
-# - Showtime provides better reliability and easier management
-# - See .github/workflows/showtime.yml for the replacement
-# - Migration guide: https://github.com/mistercrunch/superset-showtime
-
-# Example manual trigger:
-# gh workflow run ephemeral-env.yml --ref fix_ephemerals --field label_name="testenv-up" --field issue_number=666
-
-on:
-  pull_request_target:
-    types:
-      - labeled
-  workflow_dispatch:
-    inputs:
-      label_name:
-        description: 'Label name to simulate label-based /testenv trigger'
-        required: true
-        default: 'testenv-up'
-      issue_number:
-        description: 'Issue or PR number'
-        required: true
-
-jobs:
-  ephemeral-env-label:
-    concurrency:
-      group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}-label
-      cancel-in-progress: true
-    name: Evaluate ephemeral env label trigger
-    runs-on: ubuntu-24.04
-    permissions:
-      pull-requests: write
-    outputs:
-      slash-command: ${{ steps.eval-label.outputs.result }}
-      feature-flags: ${{ steps.eval-feature-flags.outputs.result }}
-      sha: ${{ steps.get-sha.outputs.sha }}
-    env:
-      DOCKERHUB_USER: ${{ secrets.DOCKERHUB_USER }}
-      DOCKERHUB_TOKEN: ${{ secrets.DOCKERHUB_TOKEN }}
-
-    steps:
-      - name: Check for the "testenv-up" label
-        id: eval-label
-        run: |
-          if [[ "${{ github.event_name }}" == "workflow_dispatch" ]]; then
-            LABEL_NAME="${INPUT_LABEL_NAME}"
-          else
-            LABEL_NAME="${{ github.event.label.name }}"
-          fi
-
-          echo "Evaluating label: $LABEL_NAME"
-
-          if [[ "$LABEL_NAME" == "testenv-up" ]]; then
-            echo "result=up" >> $GITHUB_OUTPUT
-          else
-            echo "result=noop" >> $GITHUB_OUTPUT
-          fi
-
-        env:
-          INPUT_LABEL_NAME: ${{ github.event.inputs.label_name }}
-      - name: Get event SHA
-        id: get-sha
-        if: steps.eval-label.outputs.result == 'up'
-        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
-        with:
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          script: |
-            let prSha;
-
-            // If event is workflow_dispatch, use the issue_number from inputs
-            if (context.eventName === "workflow_dispatch") {
-              const prNumber = "${{ github.event.inputs.issue_number }}";
-              if (!prNumber) {
-                console.log("No PR number found.");
-                return;
-              }
-
-              // Fetch PR details using the provided issue_number
-              const { data: pr } = await github.rest.pulls.get({
-                owner: context.repo.owner,
-                repo: context.repo.repo,
-                pull_number: prNumber
-              });
-
-              prSha = pr.head.sha;
-            } else {
-              // If it's not workflow_dispatch, use the PR head sha from the event
-              prSha = context.payload.pull_request.head.sha;
-            }
-
-            console.log(`PR SHA: ${prSha}`);
-            core.setOutput("sha", prSha);
-
-      - name: Looking for feature flags in PR description
-        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
-        id: eval-feature-flags
-        if: steps.eval-label.outputs.result == 'up'
-        with:
-          script: |
-            const description = context.payload.pull_request
-              ? context.payload.pull_request.body || ''
-              : context.payload.inputs.pr_description || '';
-
-            const pattern = /FEATURE_(\w+)=(\w+)/g;
-            let results = [];
-            [...description.matchAll(pattern)].forEach(match => {
-              const config = {
-                name: `SUPERSET_FEATURE_${match[1]}`,
-                value: match[2],
-              };
-              results.push(config);
-            });
-
-            return results;
-
-      - name: Reply with confirmation comment
-        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
-        if: steps.eval-label.outputs.result == 'up'
-        with:
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          script: |
-            const action = '${{ steps.eval-label.outputs.result }}';
-            const user = context.actor;
-            const runId = context.runId;
-            const workflowUrl = `${context.serverUrl}/${context.repo.owner}/${context.repo.repo}/actions/runs/${runId}`;
-
-            const issueNumber = context.payload.pull_request
-              ? context.payload.pull_request.number
-              : context.payload.inputs.issue_number;
-
-            if (!issueNumber) {
-              throw new Error("Issue number is not available.");
-            }
-
-            const body = `⚠️ **DEPRECATED WORKFLOW** ⚠️\n\n@${user} This workflow is deprecated! Please use the new **Superset Showtime** system instead:\n\n` +
-              `- Replace "testenv-up" label with "🎪 trigger-start"\n` +
-              `- Better reliability and easier management\n` +
-              `- See https://github.com/mistercrunch/superset-showtime for details\n\n` +
-              `Processing your ephemeral environment request [here](${workflowUrl}). Action: **${action}**.` +
-              ` More information on [how to use or configure ephemeral environments]` +
-              `(https://superset.apache.org/docs/contributing/howtos/#github-ephemeral-environments)`;
-
-
-            await github.rest.issues.createComment({
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              issue_number: issueNumber,
-              body,
-            });
-
-  ephemeral-docker-build:
-    concurrency:
-      group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}-build
-      cancel-in-progress: true
-    needs: ephemeral-env-label
-    if: needs.ephemeral-env-label.outputs.slash-command == 'up'
-    name: ephemeral-docker-build
-    runs-on: ubuntu-24.04
-    steps:
-      - name: "Checkout ${{ github.ref }} ( ${{ needs.ephemeral-env-label.outputs.sha }} : ${{steps.get-sha.outputs.sha}} )"
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
-        with:
-          ref: ${{ needs.ephemeral-env-label.outputs.sha }}
-          persist-credentials: false
-
-      - name: Setup Docker Environment
-        uses: ./.github/actions/setup-docker
-        with:
-          dockerhub-user: ${{ secrets.DOCKERHUB_USER }}
-          dockerhub-token: ${{ secrets.DOCKERHUB_TOKEN }}
-          build: "true"
-          install-docker-compose: "false"
-
-      - name: Setup supersetbot
-        uses: ./.github/actions/setup-supersetbot/
-
-      - name: Build ephemeral env image
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: |
-          supersetbot docker \
-            --push \
-            --load \
-            --preset ci \
-            --platform  linux/amd64 \
-            --context-ref "$RELEASE" \
-            --extra-flags "--build-arg INCLUDE_CHROMIUM=false"
-
-      - name: Configure AWS credentials
-        uses: aws-actions/configure-aws-credentials@8df5847569e6427dd6c4fb1cf565c83acfa8afa7 # v6
-        with:
-          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
-          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
-          aws-region: us-west-2
-
-      - name: Login to Amazon ECR
-        id: login-ecr
-        uses: aws-actions/amazon-ecr-login@fa648b43de3d4d023bcb3f89ed6940096949c419 # v2
-
-      - name: Load, tag and push image to ECR
-        id: push-image
-        env:
-          ECR_REGISTRY: ${{ steps.login-ecr.outputs.registry }}
-          ECR_REPOSITORY: superset-ci
-          IMAGE_TAG: apache/superset:${{ needs.ephemeral-env-label.outputs.sha }}-ci
-          PR_NUMBER: ${{ github.event.inputs.issue_number || github.event.pull_request.number }}
-        run: |
-          docker tag $IMAGE_TAG $ECR_REGISTRY/$ECR_REPOSITORY:pr-$PR_NUMBER-ci
-          docker push -a $ECR_REGISTRY/$ECR_REPOSITORY
-
-  ephemeral-env-up:
-    needs: [ephemeral-env-label, ephemeral-docker-build]
-    if: needs.ephemeral-env-label.outputs.slash-command == 'up'
-    name: Spin up an ephemeral environment
-    runs-on: ubuntu-24.04
-    permissions:
-      contents: read
-      pull-requests: write
-
-    steps:
-      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
-        with:
-          persist-credentials: false
-
-      - name: Configure AWS credentials
-        uses: aws-actions/configure-aws-credentials@8df5847569e6427dd6c4fb1cf565c83acfa8afa7 # v6
-        with:
-          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
-          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
-          aws-region: us-west-2
-
-      - name: Login to Amazon ECR
-        id: login-ecr
-        uses: aws-actions/amazon-ecr-login@fa648b43de3d4d023bcb3f89ed6940096949c419 # v2
-
-      - name: Check target image exists in ECR
-        id: check-image
-        continue-on-error: true
-        env:
-          PR_NUMBER: ${{ github.event.inputs.issue_number || github.event.pull_request.number }}
-        run: |
-          aws ecr describe-images \
-          --registry-id $(echo "${{ steps.login-ecr.outputs.registry }}" | grep -Eo "^[0-9]+") \
-          --repository-name superset-ci \
-          --image-ids imageTag=pr-$PR_NUMBER-ci
-
-      - name: Fail on missing container image
-        if: steps.check-image.outcome == 'failure'
-        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
-        with:
-          github-token: ${{ github.token }}
-          script: |
-            const errMsg = '@${{ github.event.comment.user.login }} Container image not yet published for this PR. Please try again when build is complete.';
-            github.rest.issues.createComment({
-              issue_number: ${{ github.event.inputs.issue_number || github.event.pull_request.number }},
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              body: errMsg
-            });
-            core.setFailed(errMsg);
-
-      - name: Fill in the new image ID in the Amazon ECS task definition
-        id: task-def
-        uses: aws-actions/amazon-ecs-render-task-definition@6853cfae8c3a7d978fbf68b5a55453395541dfbb # v1
-        with:
-          task-definition: .github/workflows/ecs-task-definition.json
-          container-name: superset-ci
-          image: ${{ steps.login-ecr.outputs.registry }}/superset-ci:pr-${{ github.event.inputs.issue_number || github.event.pull_request.number }}-ci
-
-      - name: Update env vars in the Amazon ECS task definition
-        run: |
-          cat <<< "$(jq '.containerDefinitions[0].environment += ${{ needs.ephemeral-env-label.outputs.feature-flags }}' < ${{ steps.task-def.outputs.task-definition }})" > ${{ steps.task-def.outputs.task-definition }}
-
-      - name: Describe ECS service
-        id: describe-services
-        run: |
-          echo "active=$(aws ecs describe-services --cluster superset-ci --services pr-${INPUT_ISSUE_NUMBER}-service | jq '.services[] | select(.status == "ACTIVE") | any')" >> $GITHUB_OUTPUT
-        env:
-          INPUT_ISSUE_NUMBER: ${{ github.event.inputs.issue_number || github.event.pull_request.number }}
-      - name: Create ECS service
-        id: create-service
-        if: steps.describe-services.outputs.active != 'true'
-        env:
-          ECR_SUBNETS: subnet-0e15a5034b4121710,subnet-0e8efef4a72224974
-          ECR_SECURITY_GROUP: sg-092ff3a6ae0574d91
-          PR_NUMBER: ${{ github.event.inputs.issue_number || github.event.pull_request.number }}
-        run: |
-          aws ecs create-service \
-          --cluster superset-ci \
-          --service-name pr-$PR_NUMBER-service \
-          --task-definition superset-ci \
-          --launch-type FARGATE \
-          --desired-count 1 \
-          --platform-version LATEST \
-          --network-configuration "awsvpcConfiguration={subnets=[$ECR_SUBNETS],securityGroups=[$ECR_SECURITY_GROUP],assignPublicIp=ENABLED}" \
-          --tags key=pr,value=$PR_NUMBER key=github_user,value=${{ github.actor }}
-      - name: Deploy Amazon ECS task definition
-        id: deploy-task
-        uses: aws-actions/amazon-ecs-deploy-task-definition@a310a830f5c14e583e35d84e4e1ec7dd177c3c9c # v2
-        with:
-          task-definition: ${{ steps.task-def.outputs.task-definition }}
-          service: pr-${{ github.event.inputs.issue_number || github.event.pull_request.number }}-service
-          cluster: superset-ci
-          wait-for-service-stability: true
-          wait-for-minutes: 10
-
-      - name: List tasks
-        id: list-tasks
-        run: |
-          echo "task=$(aws ecs list-tasks --cluster superset-ci --service-name pr-${INPUT_ISSUE_NUMBER}-service | jq '.taskArns | first')" >> $GITHUB_OUTPUT
-        env:
-          INPUT_ISSUE_NUMBER: ${{ github.event.inputs.issue_number || github.event.pull_request.number }}
-      - name: Get network interface
-        id: get-eni
-        run: |
-          echo "eni=$(aws ecs describe-tasks --cluster superset-ci --tasks ${{ steps.list-tasks.outputs.task }} | jq '.tasks[0].attachments[0].details | map(select(.name=="networkInterfaceId"))[0].value')" >> $GITHUB_OUTPUT
-      - name: Get public IP
-        id: get-ip
-        run: |
-          echo "ip=$(aws ec2 describe-network-interfaces --network-interface-ids ${{ steps.get-eni.outputs.eni }} | jq -r '.NetworkInterfaces | first | .Association.PublicIp')" >> $GITHUB_OUTPUT
-      - name: Comment (success)
-        if: ${{ success() }}
-        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
-        with:
-          github-token: ${{github.token}}
-          script: |
-            const issue_number = context.payload.inputs?.issue_number || context.issue.number;
-            github.rest.issues.createComment({
-              issue_number: issue_number,
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              body: `@${{ github.actor }} Ephemeral environment spinning up at http://${{ steps.get-ip.outputs.ip }}:8080. Credentials are 'admin'/'admin'. Please allow several minutes for bootstrapping and startup.`
-            });
-      - name: Comment (failure)
-        if: ${{ failure() }}
-        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
-        with:
-          github-token: ${{github.token}}
-          script: |
-            const issue_number = context.payload.inputs?.issue_number || context.issue.number;
-            github.rest.issues.createComment({
-              issue_number: issue_number,
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              body: '@${{ github.event.inputs.user_login || github.event.comment.user.login }} Ephemeral environment creation failed. Please check the Actions logs for details.'
-            })