feat: Apply localization to Login, Dashboard, and Navigation (Phase 9 - Batch 1)

**Pages Localized:**
- Login page: All UI strings (titles, labels, buttons, links)
- Dashboard page: Welcome message, quick actions, daily summary, predictions
- AppShell: Connection status and presence indicators
- MobileNav: Menu items and app branding
- TabBar: Bottom navigation labels

**Translation Files:**
- Created dashboard.json for all 5 languages (en, es, fr, pt, zh)
- Enhanced common.json with navigation and connection strings
- Updated i18n config to include dashboard namespace

**Languages Supported:**
- English, Spanish, French, Portuguese, Chinese (Simplified)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

maternal-web/locales/en/common.json

@@ -57,10 +57,23 @@
   },
   "navigation": {
     "home": "Home",
+    "dashboard": "Dashboard",
     "tracking": "Tracking",
+    "trackActivity": "Track Activity",
+    "track": "Track",
     "ai": "AI Assistant",
+    "aiChat": "AI Chat",
     "family": "Family",
     "insights": "Insights",
-    "settings": "Settings"
+    "children": "Children",
+    "settings": "Settings",
+    "logout": "Logout"
+  },
+  "connection": {
+    "syncActive": "Real-time sync active",
+    "syncDisconnected": "Real-time sync disconnected",
+    "live": "Live",
+    "offline": "Offline",
+    "familyMembersOnline": "{{count}} family members online"
   }
 }