refactor: UI consistency — shared CSS, design system colors, no inline styles

Phase 1: Extract 6 shared CSS modules (table-section, log-panel,
rate-colors, refresh-indicator, chart-card, section-card) eliminating
~135 duplicate class definitions across 11 files.

Phase 2: Replace all hardcoded hex colors in CSS modules with design
system variables. Strip ~55 hex fallbacks from var() patterns. Fix 4
undefined variable names (--accent, --bg-base, --surface, --bg-surface-raised).

Phase 3: Replace ~45 hardcoded hex values in ProcessDiagram SVG
components with var() CSS custom properties. Fix Dashboard.tsx color prop.

Phase 4: Create CSS modules for AdminLayout, DatabaseAdminPage,
OidcCallback (previously 100% inline). Extract shared PageLoader
component (replaces 3 copy-pasted spinner patterns). Move AppsTab
static inline styles to CSS classes. Extract LayoutShell StarredList styles.

58 files changed, net -219 lines.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/router.tsx

@@ -6,7 +6,7 @@ import { OidcCallback } from './auth/OidcCallback';
 import { LayoutShell } from './components/LayoutShell';
 import { config } from './config';
 import { lazy, Suspense } from 'react';
-import { Spinner } from '@cameleer/design-system';
+import { PageLoader } from './components/PageLoader';
 
 const ExchangesPage = lazy(() => import('./pages/Exchanges/ExchangesPage'));
 const DashboardPage = lazy(() => import('./pages/DashboardTab/DashboardPage'));
@@ -23,7 +23,7 @@ const SwaggerPage = lazy(() => import('./pages/Swagger/SwaggerPage'));
 
 function SuspenseWrapper({ children }: { children: React.ReactNode }) {
   return (
-    <Suspense fallback={<div style={{ display: 'flex', justifyContent: 'center', padding: '4rem' }}><Spinner size="lg" /></div>}>
+    <Suspense fallback={<PageLoader />}>
       {children}
     </Suspense>
   );