feat: Complete comprehensive localization of all tracking and management pages

- Feeding page: 47+ strings localized with validation, success/error messages
- Medicine page: 44 strings localized with unit conversion support
- Sleep page: Already localized (verified)
- Diaper page: Already localized (verified)
- Activity page: Already localized (verified)
- AI Assistant: 51 strings localized including chat interface and suggested questions
- Children page: 38 strings fully localized with gender labels
- Family page: 42 strings localized with role management
- Insights page: 41 strings localized including charts and analytics

Added translation files:
- locales/en/ai.json (44 keys)
- locales/en/family.json (42 keys)
- locales/en/insights.json (41 keys)

Updated translation files:
- locales/en/tracking.json (added feeding, health/medicine sections)
- locales/en/children.json (verified complete)

All pages now use useTranslation hook with proper namespaces.
All user-facing text externalized and ready for multi-language support.

maternal-web/locales/en/family.json

@@ -0,0 +1,43 @@
+{
+  "pageTitle": "Family",
+  "pageSubtitle": "Manage your family members and share access",
+  "buttons": {
+    "joinFamily": "Join Family",
+    "inviteMember": "Invite Member",
+    "copyCode": "Copy Code",
+    "inviteFirstMember": "Invite First Member"
+  },
+  "shareCode": {
+    "title": "Family Share Code",
+    "description": "Share this code with family members to give them access to your family's data"
+  },
+  "members": {
+    "title": "Family Members ({{count}})",
+    "noMembers": "No family members yet",
+    "noMembersDescription": "Invite family members to collaborate on child care",
+    "youLabel": "You",
+    "removeAriaLabel": "Remove {{name}} from family"
+  },
+  "roles": {
+    "parent": "Parent",
+    "caregiver": "Caregiver",
+    "viewer": "Viewer"
+  },
+  "messages": {
+    "shareCodeCopied": "Share code copied to clipboard!",
+    "shareCodeCopyFailed": "Failed to copy share code",
+    "invitationSent": "Invitation sent successfully!",
+    "joinedFamily": "Successfully joined family!",
+    "memberRemoved": "Member removed successfully",
+    "noFamilyFound": "No family found. Please complete onboarding first.",
+    "failedToLoad": "Failed to load family information",
+    "noFamilyId": "No family ID found",
+    "failedToInvite": "Failed to send invitation",
+    "failedToJoin": "Failed to join family",
+    "failedToRemove": "Failed to remove member"
+  },
+  "placeholders": {
+    "unknownUser": "Unknown User",
+    "noEmail": "No email"
+  }
+}