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/app/children/page.tsx

@@ -235,6 +235,7 @@ export default function ChildrenPage() {
                       <Box sx={{ display: 'flex', flexDirection: { xs: 'column', sm: 'row' }, alignItems: { xs: 'center', sm: 'flex-start' }, gap: { xs: 1, sm: 2 } }}>
                         <Avatar
                           src={child.photoUrl}
+                          alt={child.photoAlt || `Photo of ${child.name}`}
                           sx={{
                             width: { xs: 48, sm: 64 },
                             height: { xs: 48, sm: 64 },
@@ -262,10 +263,10 @@ export default function ChildrenPage() {
                       </Box>
 
                       <Box sx={{ display: 'flex', gap: 1, mt: 2, justifyContent: { xs: 'center', sm: 'flex-start' } }}>
-                        <IconButton size="small" color="primary" onClick={() => handleEditChild(child)}>
+                        <IconButton size="medium" color="primary" onClick={() => handleEditChild(child)} sx={{ minWidth: 48, minHeight: 48 }}>
                           <Edit />
                         </IconButton>
-                        <IconButton size="small" color="error" onClick={() => handleDeleteClick(child)}>
+                        <IconButton size="medium" color="error" onClick={() => handleDeleteClick(child)} sx={{ minWidth: 48, minHeight: 48 }}>
                           <Delete />
                         </IconButton>
                       </Box>