Stable selectors for Grafana Pathfinder tutorials (3 anchors, 4 tutorials)

[Pathfinder](https://grafana.com/docs/learning-journeys/) tutorials anchor their steps to DOM selectors. We've identified that the guides mentioned below target UI this plugin renders (audit: grafana/grafana#129672). Weak anchors (text/placeholder/positional) break silently when copy or layout changes in your plugin however data-testids give us a more robust path forwards.

## Add `data-testid`s to the following JSX

Any value works — we'll retarget the tutorials to whatever you pick.

| element (current weak anchor) | tutorials | where (at 2026-08-04/05) |
|---|---|---|
| `[aria-label='Query editor owner']` | github-visualize-lj/build-issues-panel, github-visualize-lj/build-pr-panel +1 | `src/components/selectors.ts:12` |
| `[aria-label='Query editor repository']` | github-visualize-lj/build-issues-panel, github-visualize-lj/build-pr-panel +1 | `src/components/selectors.ts:15` |
| `input[placeholder='Personal Access Token']` | github-data-source-lj/config-github-datasource | `src/views/ConfigEditor.tsx:37`
`src/views/ConfigEditor.tsx:127` |

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If you've any questions please reach out in the #proj-pathfinder-selectors slack channel.

Start with the JSX around src/components/selectors.ts:12 and :15, then inspect src/views/ConfigEditor.tsx:37 and :127. Add stable data-testid attributes to the three listed UI elements, using any values, and verify the attributes are present where the Pathfinder tutorials currently rely on weak selectors.

Written by the indexing model from the issue text.