fix(audit-wave-9): standardize on Sheet for previews; doctrine in CLAUDE.md

Swap the one outlier (client-interests-tab.tsx) from Vaul Drawer to
Sheet side=right so every detail-preview surface uses the same
primitive. Document the doctrine: Sheet for side panels on both desktop
and mobile; Vaul Drawer reserved for mobile-only bottom-sheet UX
(currently just MoreSheet).

Closes ui/ux M11.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/dashboard/source-conversion-chart.tsx

@@ -5,6 +5,7 @@ import { useQuery } from '@tanstack/react-query';
 import { apiFetch } from '@/lib/api/client';
 import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
 import { Skeleton } from '@/components/ui/skeleton';
+import { formatEnum } from '@/lib/constants';
 
 interface SourceRow {
   source: string;
@@ -57,7 +58,7 @@ export function SourceConversionChart() {
           <ul className="space-y-3">
             {rows.map((r) => {
               const pct = Math.round(r.conversionRate * 100);
-              const label = r.source.replace(/_/g, ' ').replace(/\b\w/g, (c) => c.toUpperCase());
+              const label = formatEnum(r.source);
               return (
                 <li key={r.source} className="space-y-1">
                   <div className="flex items-center justify-between text-xs">