Releases: emit a pre-rendered link field so annotation tooltips can show clickable links

[KnutZuidema]

Use case

We use the Releases query type as a Grafana annotation source on dashboards, so deploys of a service show up as vertical markers on every panel. The natural next step from a marker is "take me to the release notes on GitHub" — i.e. a clickable link in the annotation tooltip pointing at the release page.

Current behavior

The Releases frame exposes a url field containing the release page URL (e.g. https://github.com/org/repo/releases/tag/v1). With the annotation mapping

"mappings": {
  "time": { "source": "field", "value": "published_at" },
  "text": { "source": "field", "value": "url" }
}

the tooltip shows the URL as plain text. It is not clickable.

Why the obvious workarounds don't apply

• Grafana's annotation tooltip (AnnotationTooltip2.tsx) renders the text field via dangerouslySetInnerHTML={{ __html: textUtil.sanitize(text) }} and the surrounding CSS even styles a elements. So an HTML anchor like <a href="...">v2026.05.29.2</a> in text would render as a clickable link.
• However, the GitHub plugin's Releases frame (pkg/github/releases.go) only emits plain string fields (name, tag, url, …).
• Grafana's standard annotation mapping (standardAnnotationSupport.ts) lets the user pick one field per annotation key (time, text, tags, …) — there is no template/concat support, so a user cannot produce <a href="{url}">{tag}</a> from the existing fields.

The net effect: there is no user-side configuration that makes the link clickable.

Requested change

Add one or more pre-formatted link fields to the Releases frame, e.g.:

• html_link — HTML anchor: <a href="{url}">{tag}</a> (or {name} if non-empty, falling back to {tag})
• markdown_link — markdown: [{tag}]({url})

Either is sufficient on its own. HTML is the safer bet because the annotation tooltip renders HTML directly; markdown would only help in places that run a markdown renderer.

Users could then pick html_link (or markdown_link) as the annotation text field and get a clickable, descriptively-labelled link in the tooltip.

Scope

Releases is the immediate need (release annotations are a very common use case), but the same applies to:

• Tags
• Commits
• Pull requests
• Issues

…all of which are commonly used as annotation sources and all of which expose a URL but not a pre-formatted link.

Alternatives considered

• Switch to the Infinity datasource to call the GitHub REST API and synthesize an html_link column — needs a GitHub PAT configured per Grafana instance and re-implements pagination, caching, etc. that this plugin already handles.
• Auto-linkify bare URLs in Grafana itself — would have to be filed against grafana/grafana, has wider implications, and doesn't help users who want tag as the link label rather than the raw URL.

A pre-rendered link field on the existing frame is the smallest, most local fix.

Environment

• Grafana 12.3.3
• grafana-github-datasource (latest at time of filing)