feat(browser-hand): implement Browser Hand UI components

Add complete Browser Hand UI system for browser automation:

Components:
- BrowserHandCard: Main card with status display and screenshot preview
- TaskTemplateModal: Template selection and parameter configuration
- ScreenshotPreview: Screenshot display with fullscreen capability

Templates:
- Basic operations: navigate, screenshot, form fill, click, execute JS
- Scraping: text, list, images, links, tables
- Automation: login+action, multi-page, monitoring, pagination

Features:
- 15 built-in task templates across 3 categories
- Real-time execution status with progress bar
- Screenshot preview with zoom and fullscreen
- Integration with HandsPanel for seamless UX
- Zustand store for state management
- Comprehensive test coverage (16 tests)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

desktop/src/components/HandsPanel.tsx

@@ -10,6 +10,7 @@
 import { useState, useEffect, useCallback } from 'react';
 import { useGatewayStore, type Hand, type HandRequirement } from '../store/gatewayStore';
 import { Zap, RefreshCw, ChevronRight, CheckCircle, XCircle, Loader2, AlertTriangle, Settings } from 'lucide-react';
+import { BrowserHandCard } from './BrowserHand';
 
 // === Status Badge Component ===
 
@@ -457,15 +458,25 @@ export function HandsPanel() {
 
       {/* Hand Cards Grid */}
       <div className="grid gap-3">
-        {hands.map((hand) => (
-          <HandCard
-            key={hand.id}
-            hand={hand}
-            onDetails={handleDetails}
-            onActivate={handleActivate}
-            isActivating={activatingHandId === hand.id}
-          />
-        ))}
+        {hands.map((hand) => {
+          // Check if this is a Browser Hand
+          const isBrowserHand = hand.id === 'browser' || hand.name === 'Browser' || hand.name?.toLowerCase().includes('browser');
+
+          return isBrowserHand ? (
+            <BrowserHandCard
+              key={hand.id}
+              hand={hand}
+            />
+          ) : (
+            <HandCard
+              key={hand.id}
+              hand={hand}
+              onDetails={handleDetails}
+              onActivate={handleActivate}
+              isActivating={activatingHandId === hand.id}
+            />
+          );
+        })}
       </div>
 
       {/* Details Modal */}