246. Indexer health summary panels

Motivation

The indexer admin console could fetch connectivity profiles and source-reputation rows, but operators only saw those responses in the generic activity log.
ERD_INDEXERS_CHECKLIST.md still leaves the health dashboard slice open because the UI was missing the visible status badges and summary panels described by ERD_INDEXERS.md.
The next efficient step is to render those existing API reads directly in /indexers so operators can review health state without leaving the page or parsing raw JSON logs.

Add local UI state for the latest connectivity profile and fetched reputation rows alongside the existing health-event state.
Render a connectivity summary card with a status badge, dominant error, latency bands, and recent success-rate snapshots.
Render source-reputation cards for the selected window and keep health-event drill-down unchanged.
Leave notification delivery out of scope for this slice; the health checklist item remains open until email/webhook hooks exist.

Added unit coverage for connectivity badge-class mapping and percent formatting helpers in the indexer UI logic module.
Extended the /indexers route smoke test to assert the new health summary headings render.
Full just ci and just ui-e2e remain the end-to-end verification gates.

No new emitters were added.
This slice improves operator visibility by presenting already-collected connectivity and reputation telemetry directly in the admin console.

Risk is limited to UI state/rendering changes over existing API calls.
Rollback is a straightforward revert of the new state/rendering helpers and task-record updates if the console regresses.