admin: overview redesign, device scope, one formatting contract (milestone 39)

The Overview page takes the decided visual language (specs/ui-visual-redesign.md): four centred totals with their Activity links, a smoothed area chart of total and blocked queries with point hover and a tooltip centred beside the point, a stacked client chart in eight distinct hues plus one Other band that is always a series, and a card row with the cache hit rate, the query types as a single-hue ramp ring, and the upstream breakdown. The count axis grows its margin with the widest grouped tick and draws whole-number ticks only.

GET /api/overview takes a client parameter; the scoped read uses idx_query_log_ts and the cache keeps scoped slots. The device selector beside the period selector is URL state, so a scoped view is a link, and the tile links carry the scope into Activity. The route reduces a pasted IPv6 scope to the RFC 5952 spelling the logger stores, mapped addresses included, and drops anything that is not an address. A failed device list says so under the selector with a retry.

All measured quantities go through admin/src/lib/format.ts: grouped counts, two-decimal percentages, one-decimal rates, durations as the two largest nonzero units. Identifiers, configured values and preset labels render as written; the module header states that scope. A sweep test refuses toFixed, toLocaleString, Intl.NumberFormat and padStart anywhere else.

Chrome: one 4px radius from the metrics constants, shared Card with a prominent title and a one-line description on every panel, the settings form sections on the same card with a floated legend, the sidebar grouped into Monitoring and System with a status block (protection, queries per minute on Overview, uptime), keyboard-focusable table scroll wrappers, and the accent darkened to 5.43:1 on its wash.

Not built: the spec's ranked-list primitive, which has no consumer and no API rows. Codex reviewed sessions B to D over five rounds (thirty-three findings fixed, thirteen rejected as non-quantities); the owner skipped a sixth round.

Claude-Session: https://claude.ai/code/session_01VTgx3a1zz1R78o4K55kkwR

admin/src/shell/diagnosticsBadge.ts

@@ -14,6 +14,7 @@
  */
 
 import type { Health } from "@/lib/types";
+import { formatCount } from "@/lib/format";
 
 export interface NavBadge {
 	/** What the badge shows. Shape and text, never colour alone. */
@@ -30,7 +31,10 @@ export function diagnosticsBadge(health: Health | undefined, pollFailed: boolean
 	if (health === undefined) return null;
 	const open = health.diagnostics.active_warnings + health.diagnostics.active_errors;
 	if (open > 0) {
-		return { text: String(open), label: `${open} active diagnostic ${open === 1 ? "event" : "events"}` };
+		return {
+			text: formatCount(open),
+			label: `${formatCount(open)} active diagnostic ${open === 1 ? "event" : "events"}`,
+		};
 	}
 	if (health.status === "degraded") return { text: "!", label: "Health degraded" };
 	return null;