milestone 29: activity — history, live and policy simulation on one surface

query log, live and lookup merge into /activity. history filters live
in the url, so a pasted link or back/forward reproduces the exact
view; the result column separates servfail and nxdomain from success
in the list. live is follow-by-default with freeze, and a streamed
row opens its in-memory provenance detail — no correlation invented
for rows sqlite has not written. lookup survives as the current
policy simulation under /activity/test. investigation links carry
absolute bounds, and the diagnostics page now honors since/until
instead of ignoring them. the old routes are gone without aliases.

admin/src/features/activity/ActivityDetailPage.tsx

@@ -0,0 +1,75 @@
+import { useQuery } from "@tanstack/react-query";
+import { Link, useParams, useSearch } from "@tanstack/react-router";
+import * as stylex from "@stylexjs/stylex";
+import InlineError from "@/lib/InlineError";
+import { queryDetailQuery } from "@/lib/queries";
+import type { QueryDetail } from "@/lib/types";
+import { styles as shared } from "@/ui/styles";
+import { colors } from "@/ui/tokens.stylex";
+import ProvenanceDetail from "./ProvenanceDetail";
+import RelatedActions from "./RelatedActions";
+import type { ActivitySearch } from "./search";
+
+const styles = stylex.create({
+	back: {
+		fontSize: "0.875rem",
+		lineHeight: "1.25rem",
+		color: colors.primaryOnSurface,
+		textDecorationLine: "none",
+	},
+	loading: {
+		marginTop: "1rem",
+		color: colors.textMuted,
+	},
+});
+
+/**
+ * The way back to the investigation, not to a bare list. The originating
+ * Activity search rides in this route's own search, so the reader returns to
+ * the mode, the filters and the absolute window they left — a plain `/activity`
+ * would silently widen the range they had chosen.
+ */
+function BackLink({ origin }: { origin: ActivitySearch }) {
+	return (
+		<Link to="/activity" search={origin} {...stylex.props(styles.back, shared.focusRing)}>
+			← Activity
+		</Link>
+	);
+}
+
+export default function ActivityDetailPage() {
+	const { id } = useParams({ from: "/shell/activity/queries/$id" });
+	const origin = useSearch({ from: "/shell/activity/queries/$id" });
+	const rowId = Number(id);
+	const { data, error, isPending, refetch } = useQuery(queryDetailQuery(rowId));
+
+	if (isPending) {
+		return (
+			<p {...stylex.props(styles.loading, shared.pulse)} role="status">
+				Loading query…
+			</p>
+		);
+	}
+	if (data === undefined) {
+		return (
+			<section>
+				<BackLink origin={origin} />
+				<InlineError error={error} onRetry={() => void refetch()} />
+			</section>
+		);
+	}
+
+	const detail: QueryDetail = data;
+	const { domain, client, time } = detail.request;
+
+	return (
+		<section>
+			<BackLink origin={origin} />
+			<ProvenanceDetail
+				provenance={detail}
+				persistedId={detail.id}
+				relatedActions={<RelatedActions domain={domain} client={client} ts={time} origin={origin} />}
+			/>
+		</section>
+	);
+}