style(frontend): look&feel v2 — layered shadows, sharper radii, mono data register

Colors (GSD palette) untouched. New visual vocabulary across the whole GUI:
- warm-tinted layered shadow tokens (--shadow-xs/sm/md) replacing flat rings;
  cards/dialogs framed with hairline border + real elevation
- strict radii scale: xl cards / lg inputs / md controls / 2xl dialogs;
  buttons move from pills to rounded-md
- third type register: --font-mono + tabular-nums on SQL, timers, dates, ids;
  standardized .thot-label micro-label tier
- prose: framed tables with uppercase headers, elevated code blocks
- SqlViewer badges moved from hardcoded Tailwind greens/reds to success/
  destructive token tints; ResultsPanel inline styles replaced with classes
- artifact gate: first option rendered as filled primary action

Verified offline via Playwright against a mock backend replaying a real psd
session (no VPN needed). tsc clean, 115/115 vitest.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/viewers/ResultsPanel.tsx

@@ -43,8 +43,9 @@ export function ResultsPanel({ sessionId }: Props) {
   return (
     <div>
       {/* Limit selector */}
-      <div style={{ marginBottom: 8, display: "flex", gap: 8, alignItems: "center" }}>
+      <div className="mb-2 flex items-center gap-2">
         <select
+          className="rounded-lg border border-input bg-card px-2 py-1 text-sm shadow-xs outline-none transition-[border-color,box-shadow] focus:border-primary/50 focus:ring-2 focus:ring-ring/20"
           value={limit}
           onChange={(e) =>
             setLimit(e.target.value === "all" ? 1_000_000 : Number(e.target.value))
@@ -55,7 +56,12 @@ export function ResultsPanel({ sessionId }: Props) {
           <option value="all">all</option>
         </select>
 
-        <button onClick={handleExport}>Export CSV</button>
+        <button
+          className="rounded-md border border-border/70 px-3 py-1 text-sm shadow-xs transition-colors hover:bg-accent"
+          onClick={handleExport}
+        >
+          Export CSV
+        </button>
       </div>
 
       {/* Loading / error states */}
@@ -70,8 +76,10 @@ export function ResultsPanel({ sessionId }: Props) {
       {/* Grid for everything else */}
       {data && !isScalar && (
         <>
-          <div className="ag-theme-alpine" style={{ height: 400, width: "100%" }}>
-            <AgGridReact columnDefs={columnDefs} rowData={rowData} />
+          <div className="overflow-hidden rounded-xl border border-border/70 shadow-xs">
+            <div className="ag-theme-alpine" style={{ height: 400, width: "100%" }}>
+              <AgGridReact columnDefs={columnDefs} rowData={rowData} />
+            </div>
           </div>
           {data.truncated && <div>(results truncated)</div>}
         </>