UI/UX redesign: unified refined-glass design system

- Add shared UI primitives: Button, Field/Input/Select, PageHeader,
  Section, Callout, Tabs, Disclosure
- Replace gradient buttons with single blue-accent btn-primary
- Reserve gradient text for the brand wordmark only
- Rework Scanner page onto the glass system; collapse explainer and
  glossary into a disclosure, move filters into a glass toolbar
- Restructure Ticker Detail into tabs (Analysis / Indicators / S/R)
  with chart and recommendation always visible
- Align Watchlist, Rankings, Admin, Login/Register to shared primitives
- Unify stray indigo/violet/gray accents into the blue family

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

frontend/src/components/ticker/RecommendationPanel.tsx

@@ -127,7 +127,7 @@ export function RecommendationPanel({ symbol, longSetup, shortSetup }: Recommend
       <h2 className="mb-3 text-xs font-medium uppercase tracking-widest text-gray-500">Recommendation</h2>
       <div className="glass p-5 space-y-4">
         <div className="flex flex-wrap items-center gap-4">
-          <span className="text-sm font-semibold text-indigo-300">{recommendationActionLabel(action)}</span>
+          <span className="text-sm font-semibold text-blue-300">{recommendationActionLabel(action)}</span>
           <span className={`text-sm font-semibold ${riskClass(summary?.risk_level ?? null)}`}>
             Risk: {summary?.risk_level ?? '—'}
           </span>