chore: remove the TypeScript code from the repository (#2048)

This deletes the bulk of the `codex-cli` folder and eliminates the logic
that builds the TypeScript code and bundles it into the release.

Since this PR modifies `.github/workflows/rust-release.yml`, to test
changes to the release process, I locally commented out all of the "is
this commit on upstream `main`" checks in
`scripts/create_github_release.sh` and ran:

```
./codex-rs/scripts/create_github_release.sh 0.20.0-alpha.4
```

Which kicked off:

https://github.com/openai/codex/actions/runs/16842085113

And the release artifacts appear legit!

https://github.com/openai/codex/releases/tag/rust-v0.20.0-alpha.4

.github/workflows/ci.yml

@@ -44,35 +44,10 @@ jobs:
 
       # Run all tasks using workspace filters
 
-      - name: Check TypeScript code formatting
-        working-directory: codex-cli
-        run: pnpm run format
-
-      - name: Check Markdown and config file formatting
-        run: pnpm run format
-
-      - name: Run tests
-        run: pnpm run test
-
-      - name: Lint
-        run: |
-          pnpm --filter @openai/codex exec -- eslint src tests --ext ts --ext tsx \
-            --report-unused-disable-directives \
-            --rule "no-console:error" \
-            --rule "no-debugger:error" \
-            --max-warnings=-1
-
-      - name: Type-check
-        run: pnpm run typecheck
-
-      - name: Build
-        run: pnpm run build
-
       - name: Ensure staging a release works.
-        working-directory: codex-cli
         env:
           GH_TOKEN: ${{ github.token }}
-        run: pnpm stage-release
+        run: ./codex-cli/scripts/stage_release.sh
 
       - name: Ensure root README.md contains only ASCII and certain Unicode code points
         run: ./scripts/asciicheck.py README.md