admin: reclaim the desktop header, move pause and log out to the sidebar

the header row survives only on narrow screens; on desktop its lone occupant, log out, joins pause in the sidebar footer, both full width. pause leaves the query detail page's related actions, where a global control had no business, and its hand-rolled duration dropdown becomes a react-aria menu with real keyboard navigation, dismissal and positioning.

admin/src/features/activity/RelatedActions.tsx

@@ -11,7 +11,6 @@
 
 import { Link } from "@tanstack/react-router";
 import * as stylex from "@stylexjs/stylex";
-import PauseControl from "@/features/pause/PauseControl";
 import { styles as shared } from "@/ui/styles";
 import { provenanceRelatedLink } from "./ProvenanceDetail";
 import { diagnosticsBounds, relatedBounds } from "./relatedLinks";
@@ -24,15 +23,9 @@ interface Props {
 	ts: number;
 	/** The Activity search the reader came from; its bounds win over the defaults. */
 	origin: Pick<ActivitySearch, "since" | "until">;
-	/**
-	 * This query was blocked. Pausing is a valid answer to a block the reader
-	 * disagrees with, and to nothing else here — so the control appears for a
-	 * block and not beside an allowed query it could not have caused.
-	 */
-	blocked: boolean;
 }
 
-export default function RelatedActions({ domain, client, ts, origin, blocked }: Props) {
+export default function RelatedActions({ domain, client, ts, origin }: Props) {
 	const bounds = relatedBounds(ts, origin);
 	const window = diagnosticsBounds(ts);
 	return (
@@ -61,7 +54,6 @@ export default function RelatedActions({ domain, client, ts, origin, blocked }:
 			>
 				Diagnostics around this query
 			</Link>
-			{blocked && <PauseControl />}
 		</>
 	);
 }