feat: Localize Sleep, Diaper, Activity, and Settings pages

Added comprehensive localization to tracking and settings pages:

**Translation Keys Added:**
- Sleep: locations, status, duration formatting, success/delete messages
- Diaper: conditions, rash severity and alert, success/delete messages
- Activity: activity types, form labels, placeholders
- Settings: profile, preferences, notifications, appearance, account actions
- Common: shared labels (selectChild, noChildrenAdded, etc.)

**Pages Localized:**
1. Sleep tracking page (/app/track/sleep/page.tsx)
   - All form labels and dropdowns
   - Location options (crib, bed, stroller, carrier, other)
   - Sleep status (completed/ongoing)
   - Duration display with interpolation
   - Success and delete messages

2. Diaper tracking page (/app/track/diaper/page.tsx)
   - Diaper types (wet, dirty, both, dry)
   - Conditions (normal, soft, hard, watery, mucus, blood)
   - Rash detection with severity levels
   - Alert message for diaper rash
   - Recent diapers display with translated labels

3. Activity tracking page (/app/track/activity/page.tsx)
   - Activity types (play, walk, music, reading, tummy time, outdoor, other)
   - Duration and description fields
   - Form placeholders
   - Recent activities display

4. Settings page (/app/settings/page.tsx)
   - Profile information section
   - Preferences, notifications, appearance sections
   - Account actions (logout)
   - Save/saving button states
   - Success message

All pages now support multi-language translation and are ready for
Spanish, French, Portuguese, and Chinese translations.

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

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

maternal-web/locales/en/settings.json

@@ -106,8 +106,42 @@
     "rateApp": "Rate App",
     "shareApp": "Share App"
   },
-  "save": "Save Changes",
-  "saved": "Settings saved successfully",
+  "profile": {
+    "title": "Profile Information",
+    "name": "Name",
+    "nameRequired": "Name cannot be empty",
+    "email": "Email",
+    "emailNotEditable": "Email cannot be changed"
+  },
+  "appearance": {
+    "title": "Appearance",
+    "darkMode": "Dark Mode (Coming Soon)"
+  },
+  "security": {
+    "title": "Security"
+  },
+  "sessions": {
+    "title": "Sessions"
+  },
+  "deviceTrust": {
+    "title": "Device Trust"
+  },
+  "biometric": {
+    "title": "Biometric Authentication"
+  },
+  "dataExport": {
+    "title": "Data Export"
+  },
+  "accountDeletion": {
+    "title": "Account Deletion"
+  },
+  "accountActions": {
+    "title": "Account Actions",
+    "logout": "Logout"
+  },
+  "save": "Save Preferences",
+  "saving": "Saving...",
+  "saved": "Settings saved successfully!",
   "cancel": "Cancel",
   "reset": "Reset to Default"
 }