feat: Add comprehensive accessibility improvements and medical tracking

- **EULA Persistence Fix**: Fixed EULA dialog showing on every login
  - Added eulaAcceptedAt/eulaVersion to AuthResponse interface
  - Updated login/register/getUserById endpoints to return EULA fields
  - Changed EULACheck to use refreshUser() instead of window.reload()

- **Touch Target Accessibility**: All interactive elements now meet 48x48px minimum
  - Fixed 14 undersized IconButtons across 5 files
  - Changed size="small" to size="medium" with minWidth/minHeight constraints
  - Updated children page, AI chat, analytics cards, legal viewer

- **Alt Text for Images**: Complete image accessibility for screen readers
  - Added photoAlt field to children table (Migration V009)
  - PhotoUpload component now includes alt text input field
  - All Avatar components have meaningful alt text
  - Default alt text: "Photo of {childName}", "{userName}'s profile photo"

- **Medical Tracking Consolidation**: Unified medical page with tabs
  - Medicine page now has 3 tabs: Medication, Temperature, Doctor Visit
  - Backward compatibility for legacy 'medicine' activity type
  - Created dedicated /track/growth page for physical measurements

- **Track Page Updates**:
  - Simplified to 6 options: Feeding, Sleep, Diaper, Medical, Activity, Growth
  - Fixed grid layout to 3 cards per row with minWidth: 200px
  - Updated terminology from "Medicine" to "Medical"

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

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

maternal-web/components/legal/LegalDocumentViewer.tsx

@@ -58,7 +58,7 @@ export function LegalDocumentViewer({ open, onClose, documentType, title }: Lega
     >
       <DialogTitle sx={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between' }}>
         <Typography variant="h6">{title}</Typography>
-        <IconButton onClick={onClose} size="small" aria-label="close">
+        <IconButton onClick={onClose} size="medium" sx={{ minWidth: 48, minHeight: 48 }} aria-label="close">
           <Close />
         </IconButton>
       </DialogTitle>