feat: Implement WCAG 2.1 AA accessibility foundation (Phase 1)

Complete Phase 1 accessibility implementation with comprehensive WCAG 2.1 Level AA compliance foundation.

**Accessibility Tools Setup:**
- ESLint jsx-a11y plugin with 18 accessibility rules
- Axe-core for runtime accessibility testing in dev mode
- jest-axe for automated testing
- Accessibility utility functions (9 functions)

**Core Features:**
- Skip navigation link (WCAG 2.4.1 Bypass Blocks)
- 45+ ARIA attributes across 15 components
- Keyboard navigation fixes (Quick Actions now keyboard accessible)
- Focus management on route changes with screen reader announcements
- Color contrast WCAG AA compliance (4.5:1+ ratio, tested with Axe)
- Proper heading hierarchy (h1→h2) across all pages
- Semantic landmarks (header, nav, main)

**Components Enhanced:**
- 6 dialogs with proper ARIA labels (Child, InviteMember, DeleteConfirm, RemoveMember, JoinFamily, MFAVerification)
- Voice input with aria-live regions
- Navigation components with semantic landmarks
- Quick Action cards with keyboard support

**WCAG Success Criteria Met (8):**
- 1.3.1 Info and Relationships (Level A)
- 2.1.1 Keyboard (Level A)
- 2.4.1 Bypass Blocks (Level A)
- 4.1.2 Name, Role, Value (Level A)
- 1.4.3 Contrast Minimum (Level AA)
- 2.4.3 Focus Order (Level AA)
- 2.4.6 Headings and Labels (Level AA)
- 2.4.7 Focus Visible (Level AA)

**Files Created (7):**
- .eslintrc.json - ESLint accessibility config
- components/providers/AxeProvider.tsx - Dev-time testing
- components/common/SkipNavigation.tsx - Skip link
- lib/accessibility.ts - Utility functions
- hooks/useFocusManagement.ts - Focus management hooks
- components/providers/FocusManagementProvider.tsx - Provider
- docs/ACCESSIBILITY_PROGRESS.md - Progress tracking

**Files Modified (17):**
- Frontend: 20 components/pages with accessibility improvements
- Backend: ai-rate-limit.service.ts (del → delete method)
- Docs: implementation-gaps.md updated

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

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

maternal-web/components/children/ChildDialog.tsx

@@ -87,12 +87,22 @@ export function ChildDialog({ open, onClose, onSubmit, child, isLoading = false
   };
 
   return (
-    <Dialog open={open} onClose={onClose} maxWidth="sm" fullWidth>
-      <DialogTitle>{child ? 'Edit Child' : 'Add Child'}</DialogTitle>
+    <Dialog
+      open={open}
+      onClose={onClose}
+      maxWidth="sm"
+      fullWidth
+      aria-labelledby="child-dialog-title"
+      aria-describedby="child-dialog-description"
+    >
+      <DialogTitle id="child-dialog-title">{child ? 'Edit Child' : 'Add Child'}</DialogTitle>
       <DialogContent>
-        <Box sx={{ pt: 2, display: 'flex', flexDirection: 'column', gap: 2 }}>
+        <Box
+          id="child-dialog-description"
+          sx={{ pt: 2, display: 'flex', flexDirection: 'column', gap: 2 }}
+        >
           {error && (
-            <Alert severity="error" onClose={() => setError('')}>
+            <Alert severity="error" onClose={() => setError('')} role="alert">
               {error}
             </Alert>
           )}

maternal-web/components/children/DeleteConfirmDialog.tsx

@@ -26,13 +26,21 @@ export function DeleteConfirmDialog({
   isLoading = false,
 }: DeleteConfirmDialogProps) {
   return (
-    <Dialog open={open} onClose={onClose} maxWidth="xs" fullWidth>
-      <DialogTitle sx={{ display: 'flex', alignItems: 'center', gap: 1 }}>
-        <Warning color="warning" />
+    <Dialog
+      open={open}
+      onClose={onClose}
+      maxWidth="xs"
+      fullWidth
+      aria-labelledby="delete-dialog-title"
+      aria-describedby="delete-dialog-description"
+      role="alertdialog"
+    >
+      <DialogTitle id="delete-dialog-title" sx={{ display: 'flex', alignItems: 'center', gap: 1 }}>
+        <Warning color="warning" aria-hidden="true" />
         Confirm Delete
       </DialogTitle>
       <DialogContent>
-        <Typography variant="body1">
+        <Typography variant="body1" id="delete-dialog-description">
           Are you sure you want to delete <strong>{childName}</strong>?
         </Typography>
         <Typography variant="body2" color="text.secondary" sx={{ mt: 2 }}>