Wave-5 reskin batch 5: normalize stray pixel text sizes onto the declared ladder

--text-xxs (10px) joins the ladder; every component-level text-[9|10|11px]
literal in owned components now pulls from the ladder (graph-view.tsx and
home.tsx untouched — graph stream). Cosmetic pins updated where touched.

components/sidebar.tsx

@@ -253,7 +253,7 @@ function SessionsSidebar() {
 				</button>
 
 				<div className="mx-3 mb-1 flex items-center gap-2">
-					<span className="text-[10px] uppercase tracking-widest text-muted-foreground/70">Sessions</span>
+					<span className="text-xxs uppercase tracking-widest text-muted-foreground/70">Sessions</span>
 					<span className="relative flex-1">
 						<Input
 							data-testid="session-search"