Stable selectors for Grafana Pathfinder tutorials (2 anchors, 2 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) |
|---|---|---|
| `#auth-method-select` | prometheus-lj/config-authentication | `src/components/ConfigEditor/Auth/auth-method/AuthMethodSettings.tsx:147` |
| `#connection-url` | prometheus-lj/add-data-source-url | `src/components/ConfigEditor/Connection/ConnectionSettings.tsx:40`
`src/components/ConfigEditor/Connection/ConnectionSettings.tsx:60` |

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

Start with src/components/ConfigEditor/Auth/auth-method/AuthMethodSettings.tsx:147 and src/components/ConfigEditor/Connection/ConnectionSettings.tsx:40 and :60, and inspect the JSX for the two tutorial targets. Done means each target exposes a stable data-testid that the Pathfinder tutorials can use instead of the current weak selectors.

Written by the indexing model from the issue text.