ui: show the running CoreScope version in the navigation drawer

[dborup]

Upstream source

Evaluate and port Kpa-clawbot/CoreScope#2068: show the running CoreScope version in the navigation drawer using the existing /api/health response.

Intended behaviour

• Render CoreScope <version> in the drawer footer.
• Link it to this fork's releases page, not the upstream repository.
• Put commit and build time in the tooltip when available.
• Fetch /api/health only when the drawer is opened and only after its viewport/availability gate.
• Cache the request for the page lifetime so reopening the drawer adds no requests.
• A failed, non-OK or version-less health response leaves a neutral CoreScope label rather than blank or undefined text.
• Write all remote values with textContent; do not inject health fields as HTML.

Fork-specific checks

• Confirm the current /api/health field names and semantics before implementation.
• Use the dborup/CoreScope releases URL.
• Verify the footer does not regress the drawer layout at narrow desktop/tablet widths.
• Decide separately whether the mobile More surface needs parity; do not silently add a second eager health fetch.

Verification

• Unit coverage for success, rejected fetch, non-OK response, missing version, markup-shaped values and one-request caching.
• Browser verification at supported drawer viewports.
• Existing navigation and accessibility tests remain green.

No deploy is part of this issue.

[dborup]

Draft PR #142 klar til review: CI grøn (Go Build & Test, Playwright E2E, Docker build). Nav-drawerens footer viser CoreScope <version> med link til dborup/CoreScope releases og commit/build i tooltip. /api/health hentes kun ved første åbning over breddegrænsen og caches for sidens levetid. Fejl eller "unknown" giver en neutral CoreScope. Mobil-More er uændret.

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Generated by Claude Code

[dborup]

Fixed by #142 (merged as ddae955a). The pre-existing light-theme contrast problem in the drawer header is tracked in #150.