chore(frontend): comprehensive TypeScript quality improvements (#37625)

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

.github/workflows/prefer-typescript.yml

@@ -1,70 +0,0 @@
-name: Prefer TypeScript
-
-on:
-  push:
-    branches:
-      - "master"
-      - "[0-9].[0-9]*"
-    paths:
-      - "superset-frontend/src/**"
-  pull_request:
-    types: [synchronize, opened, reopened, ready_for_review]
-    paths:
-      - "superset-frontend/src/**"
-
-# cancel previous workflow jobs for PRs
-concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}
-  cancel-in-progress: true
-
-jobs:
-  prefer_typescript:
-    if: github.ref == 'ref/heads/master' && github.event_name == 'pull_request'
-    name: Prefer TypeScript
-    runs-on: ubuntu-24.04
-    permissions:
-      contents: read
-      pull-requests: write
-    steps:
-      - name: "Checkout ${{ github.ref }} ( ${{ github.sha }} )"
-        uses: actions/checkout@v6
-        with:
-          persist-credentials: false
-          submodules: recursive
-      - name: Get changed files
-        id: changed
-        uses: ./.github/actions/file-changes-action
-        with:
-          githubToken: ${{ github.token }}
-
-      - name: Determine if a .js or .jsx file was added
-        id: check
-        run: |
-          js_files_added() {
-            jq -r '
-              map(
-                select(
-                  endswith(".js") or endswith(".jsx")
-                )
-              ) | join("\n")
-            ' ${HOME}/files_added.json
-          }
-          echo "js_files_added=$(js_files_added)" >> $GITHUB_OUTPUT
-
-      - if: steps.check.outputs.js_files_added
-        name: Add Comment to PR
-        uses: ./.github/actions/comment-on-pr
-        continue-on-error: true
-        env:
-          GITHUB_TOKEN: ${{ github.token }}
-        with:
-          msg: |
-            ### WARNING: Prefer TypeScript
-
-            Looks like your PR contains new `.js` or `.jsx` files:
-
-            ```
-            ${{steps.check.outputs.js_files_added}}
-            ```
-
-            As decided in [SIP-36](https://github.com/apache/superset/issues/9101), all new frontend code should be written in TypeScript. Please convert above files to TypeScript then re-request review.