[daily] docs: add JSDoc to isProwProfile/isRepoExcluded; wire prow-plugin-map.test.js into npm test

Two small, related improvements bundled together.

## Changes

### 1. `config-manager.js` — add JSDoc to two undocumented public functions

`isProwProfile` and `isRepoExcluded` are both exported in the `return` statement and used by `content.js` and `settings.js`, but had no documentation at all. Added `@param` / `@returns` annotations consistent with the rest of the file.

### 2. `package.json` — wire `tests/prow-plugin-map.test.js` into `npm test`

`tests/prow-plugin-map.test.js` exists with 5 tests covering structural sanity of `ProwPluginMap`, the `CommandToPlugin` reverse map, and specific command-to-plugin mappings (including the `/hold` vs `wip` correctness check). It was never included in the `npm test` script, so these tests were silently skipped on every CI run.

This is distinct from the open issues #101 and #108, which cover `background.test.js` and a new `content-logic.test.js` respectively.

All **131 unit tests** pass.

---

> [!WARNING]
> **Protected Files — Push Permission Denied**
>
> This was originally intended as a pull request, but the patch modifies protected files. A human must create the pull request manually.
>
>
> Protected files
>
> - `package.json`
>
> The push was rejected because GitHub Actions does not have `workflows` permission to push these changes, and is never allowed to make such changes, or other authorization being used does not have this permission.
>
>

Create the pull request manually

```sh
# Download the patch from the workflow run
gh run download 26473157447 -n agent -D /tmp/agent-26473157447

# Create a new branch
git checkout -b docs/config-manager-jsdoc-prow-plugin-map-test-2cccf8f9fec07b50 main

# Apply the patch (--3way handles cross-repo patches)
git am --3way /tmp/agent-26473157447/aw-docs-config-manager-jsdoc-prow-plugin-map-test.patch

# Push the branch and create the pull request
git push origin docs/config-manager-jsdoc-prow-plugin-map-test-2cccf8f9fec07b50
gh pr create --title '[daily] docs: add JSDoc to isProwProfile/isRepoExcluded; wire prow-plugin-map.test.js into npm test' --base main --head docs/config-manager-jsdoc-prow-plugin-map-test-2cccf8f9fec07b50 --repo kaovilai/github-bot-command-palette
```

> Generated by [Daily Repository Improvement](https://github.com/kaovilai/github-bot-command-palette/actions/runs/26473157447) · ● 19M · [◷](https://github.com/search?q=repo%3Akaovilai%2Fgithub-bot-command-palette+%22gh-aw-workflow-id%3A+continuous-improvement%22&type=pullrequests)