style: unify workbench typography and prepare isolated visual review

frontend/src/viewers/CtePlanViewer.tsx

@@ -5,7 +5,7 @@ import type { CtePlanCte, CtePlanFilter, CtePlanV2 } from "./artifactV2";
 
 const CHIP =
   "min-w-0 max-w-full whitespace-pre-wrap [overflow-wrap:anywhere] rounded-md bg-muted px-1.5 py-0.5 font-mono text-xs text-foreground/90";
-const FIELD_LABEL = "text-[0.65rem] font-semibold uppercase tracking-[0.08em] text-muted-foreground";
+const FIELD_LABEL = "text-xs font-semibold text-muted-foreground";
 
 function Chip({ children }: { children: ReactNode }) {
   return <span className={CHIP}>{children}</span>;

frontend/src/viewers/SchemaLinkingViewer.tsx

@@ -146,7 +146,7 @@ export function SchemaLinkingViewer({ linking }: { linking: SchemaLinking }) {
       </div>
 
       {oversized && (
-        <p className="text-sm text-amber-600">
+        <p className="text-sm text-warning">
           Too many nodes to display in the graph. Use the table instead.
         </p>
       )}

frontend/src/viewers/SqlViewer.tsx

@@ -80,7 +80,7 @@ function Block({ block }: { block: SqlBlock }) {
           className="flex shrink-0 items-center gap-1.5 border-l border-border/70 px-2.5 text-xs text-muted-foreground transition-colors hover:bg-muted/40 hover:text-foreground"
         >
           {copyState === "copied" ? (
-            <Check className="size-3.5 text-[oklch(0.47_0.12_165)]" aria-hidden="true" />
+            <Check className="size-3.5 text-success" aria-hidden="true" />
           ) : copyState === "failed" ? (
             <TriangleAlert className="size-3.5 text-destructive" aria-hidden="true" />
           ) : (