diff --git a/docs/moderation/ARCHITECTURE.md b/docs/moderation/ARCHITECTURE.md
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+# Moderation Queue Architecture
+
+## Overview
+
+The moderation queue system is a comprehensive content review platform that enables moderators to review, approve, and reject user-submitted content including park/ride submissions, photo uploads, and user reviews.
+
+## System Architecture
+
+### Core Components
+
+```
+┌─────────────────────────────────────────────────────────────┐
+│                    ModerationQueue (Root)                    │
+│  - Entry point for moderation interface                     │
+│  - Manages UI state (modals, dialogs)                       │
+│  - Delegates business logic to hooks                         │
+└────────────┬────────────────────────────────────────────────┘
+             │
+             ├─► useModerationQueueManager (Orchestrator)
+             │   └─► Combines multiple sub-hooks
+             │       ├─► useModerationFilters (Filtering)
+             │       ├─► usePagination (Page management)
+             │       ├─► useModerationQueue (Lock management)
+             │       ├─► useModerationActions (Action handlers)
+             │       ├─► useEntityCache (Entity name resolution)
+             │       └─► useProfileCache (User profile caching)
+             │
+             ├─► QueueFilters (Filter controls)
+             ├─► QueueStats (Statistics display)
+             ├─► LockStatusDisplay (Current lock info)
+             │
+             └─► QueueItem (Individual submission renderer)
+                 └─► Wrapped in ModerationErrorBoundary
+                     └─► Prevents individual failures from crashing queue
diff --git a/docs/moderation/COMPONENTS.md b/docs/moderation/COMPONENTS.md
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+# Moderation Queue Components
+
+## Component Reference
+
+### ModerationQueue (Root Component)
+
+**Location:** `src/components/moderation/ModerationQueue.tsx`
+
+**Purpose:** Root component for moderation interface. Orchestrates all sub-components and manages UI state.
+
+**Props:**
+```typescript
+interface ModerationQueueProps {
+  optimisticallyUpdateStats?: (delta: Partial<{
+    pendingSubmissions: number;
+    openReports: number;
+    flaggedContent: number;
+  }>) => void;
+}
+```
+
+**Ref API:**
+```typescript
+interface ModerationQueueRef {
+  refresh: () => void;
+}
+```
+
+**Usage:**
+```tsx
+import { useRef } from 'react';
+import { ModerationQueue } from '@/components/moderation/ModerationQueue';
+
+function AdminPanel() {
+  const queueRef = useRef<ModerationQueueRef>(null);
+  
+  return (
+    <div>
+      <button onClick={() => queueRef.current?.refresh()}>
+        Refresh Queue
+      </button>
+      <ModerationQueue ref={queueRef} />
+    </div>
+  );
+}
+```
+
+---
+
+### ModerationErrorBoundary
+
+**Location:** `src/components/error/ModerationErrorBoundary.tsx`
+
+**Purpose:** Catches React render errors in queue items, preventing full queue crashes.
+
+**Props:**
+```typescript
+interface ModerationErrorBoundaryProps {
+  children: ReactNode;
+  submissionId?: string;
+  fallback?: ReactNode;
+  onError?: (error: Error, errorInfo: ErrorInfo) => void;
+}
+```
+
+**Features:**
+- Automatic error logging
+- User-friendly error UI
+- Retry functionality
+- Copy error details button
+- Development-mode stack traces
+
+**Usage:**
+```tsx
+<ModerationErrorBoundary submissionId={item.id}>
+  <QueueItem item={item} {...props} />
+</ModerationErrorBoundary>
+```
+
+**Custom Fallback:**
+```tsx
+<ModerationErrorBoundary
+  submissionId={item.id}
+  fallback={<div>Custom error message</div>}
+  onError={(error, info) => {
+    // Send to monitoring service
+    trackError(error, info);
+  }}
+>
+  <QueueItem item={item} {...props} />
+</ModerationErrorBoundary>
+```
+
+---
+
+### QueueItem
+
+**Location:** `src/components/moderation/QueueItem.tsx`
+
+**Purpose:** Renders individual submission in queue with all interaction controls.
+
+**Props:**
+```typescript
+interface QueueItemProps {
+  item: ModerationItem;
+  isMobile: boolean;
+  actionLoading: string | null;
+  isLockedByMe: boolean;
+  isLockedByOther: boolean;
+  lockStatus: LockStatus;
+  currentLockSubmissionId?: string;
+  notes: Record<string, string>;
+  isAdmin: boolean;
+  isSuperuser: boolean;
+  queueIsLoading: boolean;
+  onNoteChange: (id: string, value: string) => void;
+  onApprove: (item: ModerationItem, action: 'approved' | 'rejected', notes?: string) => void;
+  onResetToPending: (item: ModerationItem) => void;
+  onRetryFailed: (item: ModerationItem) => void;
+  onOpenPhotos: (photos: PhotoForDisplay[], index: number) => void;
+  onOpenReviewManager: (submissionId: string) => void;
+  onOpenItemEditor: (submissionId: string) => void;
+  onClaimSubmission: (submissionId: string) => void;
+  onDeleteSubmission: (item: ModerationItem) => void;
+  onInteractionFocus: (id: string) => void;
+  onInteractionBlur: (id: string) => void;
+}
+```
+
+**Key Features:**
+- Displays submission type, status, timestamps
+- User profile with avatar
+- Validation summary (errors, warnings)
+- Lock status indicators
+- Moderator edit badges
+- Action buttons (approve, reject, claim)
+- Responsive mobile/desktop layouts
+
+**Accessibility:**
+- Keyboard navigation support
+- ARIA labels on interactive elements
+- Focus management
+- Screen reader compatible
+
+---
+
+### QueueFilters
+
+**Location:** `src/components/moderation/QueueFilters.tsx`
+
+**Purpose:** Filter and sort controls for moderation queue.
+
+**Props:**
+```typescript
+interface QueueFiltersProps {
+  activeEntityFilter: EntityFilter;
+  activeStatusFilter: StatusFilter;
+  sortConfig: SortConfig;
+  isMobile: boolean;
+  isLoading?: boolean;
+  onEntityFilterChange: (filter: EntityFilter) => void;
+  onStatusFilterChange: (filter: StatusFilter) => void;
+  onSortChange: (config: SortConfig) => void;
+  onClearFilters: () => void;
+  showClearButton: boolean;
+}
+```
+
+**Features:**
+- Entity type filter (all, reviews, submissions, photos)
+- Status filter (pending, approved, rejected, etc.)
+- Sort controls (date, type, status)
+- Clear filters button
+- Fully accessible (ARIA labels, keyboard navigation)
+
+**Usage:**
+```tsx
+<QueueFilters
+  activeEntityFilter={filters.entityFilter}
+  activeStatusFilter={filters.statusFilter}
+  sortConfig={filters.sortConfig}
+  isMobile={isMobile}
+  onEntityFilterChange={filters.setEntityFilter}
+  onStatusFilterChange={filters.setStatusFilter}
+  onSortChange={filters.setSortConfig}
+  onClearFilters={filters.clearFilters}
+  showClearButton={filters.hasActiveFilters}
+/>
+```
+
+---
+
+### ValidationSummary
+
+**Location:** `src/components/moderation/ValidationSummary.tsx`
+
+**Purpose:** Displays validation results for submission items.
+
+**Props:**
+```typescript
+interface ValidationSummaryProps {
+  item: {
+    item_type: string;
+    item_data: SubmissionItemData;
+    id?: string;
+  };
+  onValidationChange?: (result: ValidationResult) => void;
+  compact?: boolean;
+  validationKey?: number;
+}
+```
+
+**View Modes:**
+
+**Compact (for queue items):**
+- Status badges (Valid, Errors, Warnings)
+- Always-visible error details (no hover needed)
+- Minimal space usage
+
+**Detailed (for review manager):**
+- Expandable validation details
+- Full error, warning, and suggestion lists
+- Re-validate button
+
+**Usage:**
+```tsx
+{/* Compact view in queue */}
+<ValidationSummary
+  item={{
+    item_type: 'park',
+    item_data: parkData,
+    id: itemId
+  }}
+  compact={true}
+  onValidationChange={(result) => {
+    if (result.blockingErrors.length > 0) {
+      setCanApprove(false);
+    }
+  }}
+/>
+
+{/* Detailed view in editor */}
+<ValidationSummary
+  item={{
+    item_type: 'ride',
+    item_data: rideData
+  }}
+  compact={false}
+/>
+```
+
+---
+
+## Hooks Reference
+
+### useModerationQueueManager
+
+**Location:** `src/hooks/moderation/useModerationQueueManager.ts`
+
+**Purpose:** Orchestrator hook combining all moderation queue logic.
+
+**Usage:**
+```typescript
+const queueManager = useModerationQueueManager({
+  user,
+  isAdmin: isAdmin(),
+  isSuperuser: isSuperuser(),
+  toast,
+  settings: {
+    refreshMode: 'auto',
+    pollInterval: 30000,
+    refreshStrategy: 'merge',
+    preserveInteraction: true,
+    useRealtimeQueue: true,
+  },
+});
+
+// Access sub-hooks
+queueManager.filters.setEntityFilter('reviews');
+queueManager.pagination.setCurrentPage(2);
+queueManager.queue.claimSubmission(itemId);
+
+// Perform actions
+await queueManager.performAction(item, 'approved', 'Looks good!');
+await queueManager.deleteSubmission(item);
+```
+
+---
+
+### useModerationQueue
+
+**Location:** `src/hooks/useModerationQueue.ts`
+
+**Purpose:** Lock management and queue statistics.
+
+**Features:**
+- Claim/release submission locks
+- Lock expiry countdown
+- Lock status checking
+- Queue statistics
+
+**Usage:**
+```typescript
+const queue = useModerationQueue({
+  onLockStateChange: () => {
+    console.log('Lock state changed');
+  }
+});
+
+// Claim submission
+await queue.claimSubmission('submission-123');
+
+// Extend lock (adds 15 minutes)
+await queue.extendLock();
+
+// Release lock
+await queue.releaseLock('submission-123');
+
+// Check lock status
+const timeRemaining = queue.getTimeRemaining();
+const progress = queue.getLockProgress();
+```
+
+---
+
+## Testing Components
+
+### Unit Testing Example
+
+```typescript
+import { render, screen } from '@testing-library/react';
+import { ModerationErrorBoundary } from '@/components/error/ModerationErrorBoundary';
+
+describe('ModerationErrorBoundary', () => {
+  it('catches errors and shows fallback UI', () => {
+    const ThrowError = () => {
+      throw new Error('Test error');
+    };
+    
+    render(
+      <ModerationErrorBoundary submissionId="test-123">
+        <ThrowError />
+      </ModerationErrorBoundary>
+    );
+    
+    expect(screen.getByText(/queue item error/i)).toBeInTheDocument();
+    expect(screen.getByText(/test error/i)).toBeInTheDocument();
+  });
+  
+  it('shows retry button', () => {
+    const ThrowError = () => {
+      throw new Error('Test error');
+    };
+    
+    render(
+      <ModerationErrorBoundary>
+        <ThrowError />
+      </ModerationErrorBoundary>
+    );
+    
+    expect(screen.getByRole('button', { name: /retry/i })).toBeInTheDocument();
+  });
+});
+```
+
+### Integration Testing Example
+
+```typescript
+import { renderHook, act } from '@testing-library/react';
+import { useModerationQueueManager } from '@/hooks/moderation/useModerationQueueManager';
+
+describe('useModerationQueueManager', () => {
+  it('filters items correctly', async () => {
+    const { result } = renderHook(() => useModerationQueueManager(config));
+    
+    act(() => {
+      result.current.filters.setEntityFilter('reviews');
+    });
+    
+    await waitFor(() => {
+      expect(result.current.items.every(item => item.type === 'review')).toBe(true);
+    });
+  });
+});
+```
+
+---
+
+## Accessibility Guidelines
+
+### Keyboard Navigation
+
+**Queue Filters:**
+- `Tab`: Navigate between filter controls
+- `Enter`/`Space`: Open dropdown
+- `Arrow keys`: Navigate dropdown options
+- `Escape`: Close dropdown
+
+**Queue Items:**
+- `Tab`: Navigate between interactive elements
+- `Enter`/`Space`: Activate buttons
+- `Escape`: Close expanded sections
+
+### Screen Reader Support
+
+All components include:
+- Semantic HTML (`<button>`, `<label>`, `<select>`)
+- ARIA labels for icon-only buttons
+- ARIA live regions for dynamic updates
+- Proper heading hierarchy
+
+### Focus Management
+
+- Focus trapped in modals
+- Focus returned to trigger on close
+- Skip links for keyboard users
+- Visible focus indicators
+
+---
+
+## Styling Guidelines
+
+### Semantic Tokens
+
+Use design system tokens instead of hardcoded colors:
+
+```tsx
+// ❌ DON'T
+<div className="text-white bg-blue-500">
+
+// ✅ DO
+<div className="text-foreground bg-primary">
+```
+
+### Responsive Design
+
+All components support mobile/desktop layouts:
+
+```tsx
+<div className={`${isMobile ? 'flex-col' : 'flex-row'}`}>
+```
+
+### Dark Mode
+
+All components automatically adapt to light/dark mode using CSS variables.
+
+---
+
+## Performance Considerations
+
+### Memoization
+
+```tsx
+// QueueItem is memoized
+export const QueueItem = memo(({ item, ...props }) => {
+  // Component will only re-render if props change
+});
+```
+
+### Lazy Loading
+
+Large components can be lazy-loaded:
+
+```tsx
+const SubmissionReviewManager = lazy(() => 
+  import('./SubmissionReviewManager')
+);
+```
+
+### Debouncing
+
+Filters use debounced updates to reduce query load:
+
+```tsx
+const filters = useModerationFilters({
+  debounceDelay: 300, // Wait 300ms before applying filter
+});
+```
+
+---
+
+## Troubleshooting
+
+### Error Boundary Not Catching Errors
+
+**Issue:** Error boundary doesn't catch async errors or event handler errors.
+
+**Solution:** Error boundaries only catch errors during rendering, lifecycle methods, and constructors. For async errors:
+
+```tsx
+try {
+  await performAction();
+} catch (error) {
+  handleError(error); // Manual error handling
+}
+```
+
+### Lock Timer Memory Leak
+
+**Issue:** Lock timer continues after component unmount.
+
+**Solution:** Already fixed in Phase 4. Timer now checks `isMounted` flag and cleans up properly.
+
+### Validation Summary Not Updating
+
+**Issue:** Validation summary shows stale data after edits.
+
+**Solution:** Pass `validationKey` prop to force re-validation:
+
+```tsx
+<ValidationSummary
+  item={item}
+  validationKey={editCount} // Increment on each edit
+/>
+```
+
+---
+
+## References
+
+- Architecture: `docs/moderation/ARCHITECTURE.md`
+- Submission Patterns: `docs/moderation/SUBMISSION_PATTERNS.md`
+- Type Definitions: `src/types/moderation.ts`
+- Hooks: `src/hooks/moderation/`
diff --git a/docs/moderation/SUBMISSION_PATTERNS.md b/docs/moderation/SUBMISSION_PATTERNS.md
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+# Submission Patterns & Guidelines
+
+## Overview
+
+This document outlines the patterns and best practices for working with submissions in the moderation queue system.
+
+## Submission Types
+
+### 1. Content Submissions (`content_submissions`)
+
+**When to use:**
+- Creating or updating parks, rides, companies, ride models
+- Multi-item submissions with dependencies
+- Submissions requiring moderator review before going live
+
+**Data Flow:**
+```
+User Form → validateEntityData() → createSubmission() 
+  → content_submissions table 
+  → submission_items table (with dependencies)
+  → Moderation Queue
+  → Approval → process-selective-approval edge function
+  → Live entities created
+```
+
+**Example:**
+```typescript
+// Creating a park with operator dependency
+const { success } = await createParkSubmission({
+  name: "Cedar Point",
+  park_type: "theme_park",
+  operator_id: "new_operator_123", // References another item in same submission
+});
+```
+
+### 2. Photo Submissions (`photo_submissions`)
+
+**When to use:**
+- User uploading photos to existing entities
+- Photos require moderation but entity already exists
+
+**Data Flow:**
+```
+UppyPhotoSubmissionUpload 
+  → Cloudflare Direct Upload
+  → photo_submissions + photo_submission_items tables
+  → Moderation Queue
+  → Approval → Photos linked to entity
+```
+
+**Key Requirements:**
+- Must be linked to parent `content_submissions` for queue integration
+- Caption and title sanitized (plain text only, no HTML)
+- Maximum 10 photos per submission
+
+### 3. Reviews (`reviews`)
+
+**When to use:**
+- User reviewing a park or ride
+- Rating with optional text content
+
+**Data Flow:**
+```
+ReviewForm 
+  → reviews table + content_submissions (NEW)
+  → Moderation Queue
+  → Approval → Review goes live
+```
+
+**Sanitization:**
+- All review content is plain text (HTML stripped)
+- Maximum 5000 characters
+- Rating validation (0.5-5.0 scale)
+
+## When to Use Each Table
+
+### Use `content_submissions` when:
+✅ Creating new entities (parks, rides, companies)
+✅ Updating existing entities
+✅ Submissions have multi-item dependencies
+✅ Need moderator review before data goes live
+
+### Use Specialized Tables when:
+✅ **Photos**: Entity exists, just adding media (`photo_submissions`)
+✅ **Reviews**: User feedback on existing entity (`reviews` + `content_submissions`)
+✅ **Technical Specs**: Belongs to specific entity (`ride_technical_specifications`)
+
+## Validation Requirements
+
+### All Submissions Must:
+1. Pass Zod schema validation (`entityValidationSchemas.ts`)
+2. Have proper slug generation (unique, URL-safe)
+3. Include source URLs when applicable
+4. Pass duplicate detection checks
+
+### Entity-Specific Requirements:
+
+**Parks:**
+- Valid `park_type` enum
+- Valid location data (country required)
+- Opening date format validation
+
+**Rides:**
+- Must reference valid `park_id`
+- Valid `ride_type` enum
+- Opening date validation
+
+**Companies:**
+- Valid `company_type` enum
+- Country code validation
+- Founded year range check
+
+## Dependency Resolution
+
+### Dependency Types:
+1. **Same-submission dependencies**: New park references new operator (both in queue)
+2. **Existing entity dependencies**: New ride references existing park
+3. **Multi-level dependencies**: Ride → Park → Operator → Owner (4 levels)
+
+### Resolution Order:
+Dependencies are resolved using topological sorting:
+```
+1. Load all items in submission
+2. Build dependency graph
+3. Sort topologically (parents before children)
+4. Process in order
+```
+
+**Example:**
+```
+Submission contains:
+- Item A: Operator (no dependencies)
+- Item B: Park (depends on A)
+- Item C: Ride (depends on B)
+
+Processing order: A → B → C
+```
+
+## Best Practices
+
+### DO:
+✅ Use existing entities when possible (avoid duplicates)
+✅ Provide source URLs for verifiability
+✅ Write clear submission notes for moderators
+✅ Validate data on client-side before submission
+✅ Use type guards when working with `SubmissionItemData`
+
+### DON'T:
+❌ Store JSON blobs in SQL columns
+❌ Skip validation to "speed up" submissions
+❌ Create dependencies to non-existent entities
+❌ Submit without source verification
+❌ Bypass moderation queue (security risk)
+
+## Adding New Submission Types
+
+### Steps:
+1. Create type definition in `src/types/moderation.ts`
+2. Add type guard to `src/lib/moderation/typeGuards.ts`
+3. Create validation schema in `src/lib/entityValidationSchemas.ts`
+4. Add submission helper in `src/lib/entitySubmissionHelpers.ts`
+5. Update `useModerationQueueManager` query to fetch new type
+6. Create renderer component (optional, for complex UI)
+7. Add tests for new type
+
+### Example: Adding "Event" Submission Type
+
+```typescript
+// 1. Type definition (moderation.ts)
+export interface EventItemData {
+  event_id?: string;
+  name: string;
+  park_id: string;
+  start_date: string;
+  end_date: string;
+}
+
+export type SubmissionItemData = 
+  | ParkItemData 
+  | RideItemData
+  | EventItemData; // Add here
+
+// 2. Type guard (typeGuards.ts)
+export function isEventItemData(data: SubmissionItemData): data is EventItemData {
+  return 'start_date' in data && 'end_date' in data;
+}
+
+// 3. Validation (entityValidationSchemas.ts)
+const eventSchema = z.object({
+  name: z.string().min(1).max(200),
+  park_id: z.string().uuid(),
+  start_date: z.string().datetime(),
+  end_date: z.string().datetime(),
+});
+
+// 4. Submission helper (entitySubmissionHelpers.ts)
+export async function createEventSubmission(eventData: EventFormData) {
+  // Validation, submission creation logic
+}
+
+// 5. Update queue query to include events
+// (already handles all content_submissions)
+
+// 6. Optional: Create EventSubmissionDisplay component
+// 7. Add tests
+```
+
+## Migration Checklist
+
+When migrating legacy code to this pattern:
+- [ ] Remove direct database writes (use submission helpers)
+- [ ] Add validation schemas
+- [ ] Update to use `SubmissionItemData` types
+- [ ] Add type guards where needed
+- [ ] Test dependency resolution
+- [ ] Verify sanitization is applied
+- [ ] Update documentation
+
+## Security Considerations
+
+### Input Validation:
+- **Server-side validation** is mandatory (Zod schemas)
+- **Client-side validation** for UX only
+- **Never trust user input** - always validate and sanitize
+
+### Sanitization:
+- HTML stripped from user text (use `rehype-sanitize`)
+- URLs validated and optionally stripped
+- File uploads validated (type, size, count)
+- SQL injection prevented (Supabase parameterized queries)
+
+### Access Control:
+- Only moderators can approve/reject
+- Users can only submit, not self-approve
+- RLS policies enforce row-level security
+- Lock system prevents concurrent modifications
+
+## Troubleshooting
+
+### Common Issues:
+
+**"Dependency not found"**
+→ Check if parent entity exists in database or in same submission
+
+**"Validation failed"**
+→ Check Zod schema, ensure all required fields present
+
+**"Duplicate slug"**
+→ Slug generation collided, system will auto-increment
+
+**"Lock expired"**
+→ Moderator must re-claim submission to continue
+
+**"Permission denied"**
+→ Check user role (must be moderator/admin)
+
+## References
+
+- See `ARCHITECTURE.md` for system design
+- See `COMPONENTS.md` for UI component usage
+- See `../IMPLEMENTATION_COMPLETE.md` for recent changes
diff --git a/src/components/error/ModerationErrorBoundary.tsx b/src/components/error/ModerationErrorBoundary.tsx
new file mode 100644
index 00000000..4ec4ebae
--- /dev/null
+++ b/src/components/error/ModerationErrorBoundary.tsx
@@ -0,0 +1,159 @@
+import React, { Component, ErrorInfo, ReactNode } from 'react';
+import { AlertCircle, RefreshCw } from 'lucide-react';
+import { Alert, AlertDescription, AlertTitle } from '@/components/ui/alert';
+import { Button } from '@/components/ui/button';
+import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
+import { logger } from '@/lib/logger';
+
+interface ModerationErrorBoundaryProps {
+  children: ReactNode;
+  submissionId?: string;
+  fallback?: ReactNode;
+  onError?: (error: Error, errorInfo: ErrorInfo) => void;
+}
+
+interface ModerationErrorBoundaryState {
+  hasError: boolean;
+  error: Error | null;
+  errorInfo: ErrorInfo | null;
+}
+
+/**
+ * Error Boundary for Moderation Queue Components
+ * 
+ * Prevents individual queue item render errors from crashing the entire queue.
+ * Shows user-friendly error UI with retry functionality.
+ * 
+ * Usage:
+ * ```tsx
+ * <ModerationErrorBoundary submissionId={item.id}>
+ *   <QueueItem item={item} />
+ * </ModerationErrorBoundary>
+ * ```
+ */
+export class ModerationErrorBoundary extends Component<
+  ModerationErrorBoundaryProps,
+  ModerationErrorBoundaryState
+> {
+  constructor(props: ModerationErrorBoundaryProps) {
+    super(props);
+    this.state = {
+      hasError: false,
+      error: null,
+      errorInfo: null,
+    };
+  }
+
+  static getDerivedStateFromError(error: Error): Partial<ModerationErrorBoundaryState> {
+    return {
+      hasError: true,
+      error,
+    };
+  }
+
+  componentDidCatch(error: Error, errorInfo: ErrorInfo) {
+    // Log error to monitoring system
+    logger.error('Moderation component error caught by boundary', {
+      action: 'error_boundary_catch',
+      submissionId: this.props.submissionId,
+      error: error.message,
+      stack: error.stack,
+      componentStack: errorInfo.componentStack,
+    });
+
+    // Update state with error info
+    this.setState({
+      errorInfo,
+    });
+
+    // Call optional error handler
+    this.props.onError?.(error, errorInfo);
+  }
+
+  handleRetry = () => {
+    this.setState({
+      hasError: false,
+      error: null,
+      errorInfo: null,
+    });
+  };
+
+  render() {
+    if (this.state.hasError) {
+      // Custom fallback if provided
+      if (this.props.fallback) {
+        return this.props.fallback;
+      }
+
+      // Default error UI
+      return (
+        <Card className="border-red-200 dark:border-red-800 bg-red-50/50 dark:bg-red-900/10">
+          <CardHeader className="pb-3">
+            <CardTitle className="flex items-center gap-2 text-red-700 dark:text-red-300">
+              <AlertCircle className="w-5 h-5" />
+              Queue Item Error
+            </CardTitle>
+          </CardHeader>
+          <CardContent className="space-y-3">
+            <Alert variant="destructive">
+              <AlertCircle className="h-4 w-4" />
+              <AlertTitle>Failed to render submission</AlertTitle>
+              <AlertDescription>
+                <div className="mt-2 space-y-2">
+                  <p className="text-sm">
+                    {this.state.error?.message || 'An unexpected error occurred'}
+                  </p>
+                  {this.props.submissionId && (
+                    <p className="text-xs text-muted-foreground font-mono">
+                      Submission ID: {this.props.submissionId}
+                    </p>
+                  )}
+                </div>
+              </AlertDescription>
+            </Alert>
+
+            <div className="flex items-center gap-2">
+              <Button
+                variant="outline"
+                size="sm"
+                onClick={this.handleRetry}
+                className="gap-2"
+              >
+                <RefreshCw className="w-4 h-4" />
+                Retry
+              </Button>
+              <Button
+                variant="ghost"
+                size="sm"
+                onClick={() => {
+                  navigator.clipboard.writeText(
+                    JSON.stringify({
+                      error: this.state.error?.message,
+                      stack: this.state.error?.stack,
+                      submissionId: this.props.submissionId,
+                    }, null, 2)
+                  );
+                }}
+              >
+                Copy Error Details
+              </Button>
+            </div>
+
+            {process.env.NODE_ENV === 'development' && this.state.errorInfo && (
+              <details className="text-xs">
+                <summary className="cursor-pointer text-muted-foreground hover:text-foreground">
+                  Show Component Stack
+                </summary>
+                <pre className="mt-2 overflow-auto p-2 bg-muted rounded text-xs">
+                  {this.state.errorInfo.componentStack}
+                </pre>
+              </details>
+            )}
+          </CardContent>
+        </Card>
+      );
+    }
+
+    return this.props.children;
+  }
+}
diff --git a/src/components/moderation/ModerationQueue.tsx b/src/components/moderation/ModerationQueue.tsx
index 9d2cf566..9116f927 100644
--- a/src/components/moderation/ModerationQueue.tsx
+++ b/src/components/moderation/ModerationQueue.tsx
@@ -12,6 +12,7 @@ import { useIsMobile } from '@/hooks/use-mobile';
 import { useAdminSettings } from '@/hooks/useAdminSettings';
 import { useModerationQueueManager } from '@/hooks/moderation';
 import { QueueItem } from './QueueItem';
+import { ModerationErrorBoundary } from '@/components/error/ModerationErrorBoundary';
 import { QueueSkeleton } from './QueueSkeleton';
 import { LockStatusDisplay } from './LockStatusDisplay';
 import { getLockStatus } from '@/lib/moderation/lockHelpers';
@@ -199,9 +200,10 @@ export const ModerationQueue = forwardRef<ModerationQueueRef, ModerationQueuePro
         <TooltipProvider>
           <div className="space-y-6">
             {queueManager.items.map((item, index) => (
-              <QueueItem
-                key={item.id}
-                item={item}
+              <ModerationErrorBoundary key={item.id} submissionId={item.id}>
+                <QueueItem
+                  key={item.id}
+                  item={item}
                 isMobile={isMobile}
                 actionLoading={queueManager.actionLoading}
                 isLockedByMe={queueManager.queue.isLockedByMe(item.id, item.assigned_to, item.locked_until)}
@@ -221,9 +223,10 @@ export const ModerationQueue = forwardRef<ModerationQueueRef, ModerationQueuePro
                 onOpenItemEditor={handleOpenItemEditor}
                 onClaimSubmission={queueManager.queue.claimSubmission}
                 onDeleteSubmission={queueManager.deleteSubmission}
-                onInteractionFocus={(id) => queueManager.markInteracting(id, true)}
-                onInteractionBlur={(id) => queueManager.markInteracting(id, false)}
-              />
+                  onInteractionFocus={(id) => queueManager.markInteracting(id, true)}
+                  onInteractionBlur={(id) => queueManager.markInteracting(id, false)}
+                />
+              </ModerationErrorBoundary>
             ))}
           </div>
         </TooltipProvider>
diff --git a/src/components/moderation/QueueFilters.tsx b/src/components/moderation/QueueFilters.tsx
index 8e068276..8804a125 100644
--- a/src/components/moderation/QueueFilters.tsx
+++ b/src/components/moderation/QueueFilters.tsx
@@ -48,12 +48,16 @@ export const QueueFilters = ({
       <div className={`flex gap-4 flex-1 ${isMobile ? 'flex-col' : 'flex-col sm:flex-row'}`}>
         {/* Entity Type Filter */}
         <div className={`space-y-2 ${isMobile ? 'w-full' : 'min-w-[140px]'}`}>
-          <Label className={`font-medium ${isMobile ? 'text-xs' : 'text-sm'}`}>Entity Type</Label>
+          <Label htmlFor="entity-filter" className={`font-medium ${isMobile ? 'text-xs' : 'text-sm'}`}>Entity Type</Label>
           <Select 
             value={activeEntityFilter} 
             onValueChange={onEntityFilterChange}
           >
-            <SelectTrigger className={isMobile ? "h-10" : ""}>
+            <SelectTrigger 
+              id="entity-filter"
+              className={isMobile ? "h-10" : ""}
+              aria-label="Filter by entity type"
+            >
               <SelectValue>
                 <div className="flex items-center gap-2">
                   {getEntityFilterIcon(activeEntityFilter)}
@@ -92,12 +96,16 @@ export const QueueFilters = ({
 
         {/* Status Filter */}
         <div className={`space-y-2 ${isMobile ? 'w-full' : 'min-w-[120px]'}`}>
-          <Label className={`font-medium ${isMobile ? 'text-xs' : 'text-sm'}`}>Status</Label>
+          <Label htmlFor="status-filter" className={`font-medium ${isMobile ? 'text-xs' : 'text-sm'}`}>Status</Label>
           <Select 
             value={activeStatusFilter} 
             onValueChange={onStatusFilterChange}
           >
-            <SelectTrigger className={isMobile ? "h-10" : ""}>
+            <SelectTrigger 
+              id="status-filter"
+              className={isMobile ? "h-10" : ""}
+              aria-label="Filter by submission status"
+            >
               <SelectValue>
                 <span className="capitalize">{activeStatusFilter === 'all' ? 'All Status' : activeStatusFilter}</span>
               </SelectValue>
@@ -132,6 +140,7 @@ export const QueueFilters = ({
             size={isMobile ? "default" : "sm"}
             onClick={onClearFilters}
             className={`flex items-center gap-2 ${isMobile ? 'w-full h-10' : ''}`}
+            aria-label="Clear all filters"
           >
             <X className="w-4 h-4" />
             Clear Filters
diff --git a/src/components/moderation/QueueItem.tsx b/src/components/moderation/QueueItem.tsx
index 4758e1eb..3ab2f500 100644
--- a/src/components/moderation/QueueItem.tsx
+++ b/src/components/moderation/QueueItem.tsx
@@ -4,6 +4,7 @@ import { usePhotoSubmissionItems } from '@/hooks/usePhotoSubmissionItems';
 import { PhotoGrid } from '@/components/common/PhotoGrid';
 import { normalizePhotoData } from '@/lib/photoHelpers';
 import type { PhotoItem } from '@/types/photos';
+import type { PhotoForDisplay } from '@/types/moderation';
 import { getSubmissionTypeLabel } from '@/lib/moderation/entities';
 import { Button } from '@/components/ui/button';
 import { Badge } from '@/components/ui/badge';
@@ -41,7 +42,7 @@ interface QueueItemProps {
   onApprove: (item: ModerationItem, action: 'approved' | 'rejected', notes?: string) => void;
   onResetToPending: (item: ModerationItem) => void;
   onRetryFailed: (item: ModerationItem) => void;
-  onOpenPhotos: (photos: any[], index: number) => void;
+  onOpenPhotos: (photos: PhotoForDisplay[], index: number) => void;
   onOpenReviewManager: (submissionId: string) => void;
   onOpenItemEditor: (submissionId: string) => void;
   onClaimSubmission: (submissionId: string) => void;
diff --git a/src/components/moderation/SubmissionItemsList.tsx b/src/components/moderation/SubmissionItemsList.tsx
index 8516ba8c..8ccb5d3e 100644
--- a/src/components/moderation/SubmissionItemsList.tsx
+++ b/src/components/moderation/SubmissionItemsList.tsx
@@ -8,6 +8,7 @@ import { AlertCircle, Loader2 } from 'lucide-react';
 import type { SubmissionItemData } from '@/types/submissions';
 import { logger } from '@/lib/logger';
 import { getErrorMessage } from '@/lib/errorHandler';
+import { ModerationErrorBoundary } from '@/components/error/ModerationErrorBoundary';
 
 interface SubmissionItemsListProps {
   submissionId: string;
@@ -97,32 +98,34 @@ export const SubmissionItemsList = memo(function SubmissionItemsList({
   }
 
   return (
-    <div className="flex flex-col gap-3">
-      {refreshing && (
-        <div className="flex items-center gap-2 text-xs text-muted-foreground">
-          <Loader2 className="h-3 w-3 animate-spin" />
-          <span>Refreshing...</span>
-        </div>
-      )}
-      
-      {/* Show regular submission items */}
-      {items.map((item) => (
-        <div key={item.id} className={view === 'summary' ? 'border-l-2 border-primary/20 pl-3' : ''}>
-          <SubmissionChangesDisplay 
-            item={item}
-            view={view}
-            showImages={showImages}
-            submissionId={submissionId}
-          />
-        </div>
-      ))}
+    <ModerationErrorBoundary submissionId={submissionId}>
+      <div className="flex flex-col gap-3">
+        {refreshing && (
+          <div className="flex items-center gap-2 text-xs text-muted-foreground">
+            <Loader2 className="h-3 w-3 animate-spin" />
+            <span>Refreshing...</span>
+          </div>
+        )}
+        
+        {/* Show regular submission items */}
+        {items.map((item) => (
+          <div key={item.id} className={view === 'summary' ? 'border-l-2 border-primary/20 pl-3' : ''}>
+            <SubmissionChangesDisplay 
+              item={item}
+              view={view}
+              showImages={showImages}
+              submissionId={submissionId}
+            />
+          </div>
+        ))}
 
-      {/* Show photo submission if exists */}
-      {hasPhotos && (
-        <div className={view === 'summary' ? 'border-l-2 border-primary/20 pl-3' : ''}>
-          <PhotoSubmissionDisplay submissionId={submissionId} />
-        </div>
-      )}
-    </div>
+        {/* Show photo submission if exists */}
+        {hasPhotos && (
+          <div className={view === 'summary' ? 'border-l-2 border-primary/20 pl-3' : ''}>
+            <PhotoSubmissionDisplay submissionId={submissionId} />
+          </div>
+        )}
+      </div>
+    </ModerationErrorBoundary>
   );
 });
diff --git a/src/components/moderation/ValidationSummary.tsx b/src/components/moderation/ValidationSummary.tsx
index 6caa3058..e8cf3771 100644
--- a/src/components/moderation/ValidationSummary.tsx
+++ b/src/components/moderation/ValidationSummary.tsx
@@ -7,10 +7,12 @@ import { Collapsible, CollapsibleContent, CollapsibleTrigger } from '@/component
 import { validateEntityData, ValidationResult } from '@/lib/entityValidationSchemas';
 import { logger } from '@/lib/logger';
 
+import type { SubmissionItemData } from '@/types/moderation';
+
 interface ValidationSummaryProps {
   item: {
     item_type: string;
-    item_data: any;
+    item_data: SubmissionItemData;
     id?: string;
   };
   onValidationChange?: (result: ValidationResult) => void;
diff --git a/src/hooks/useModerationQueue.ts b/src/hooks/useModerationQueue.ts
index 4ebbe73f..ff2713b9 100644
--- a/src/hooks/useModerationQueue.ts
+++ b/src/hooks/useModerationQueue.ts
@@ -87,8 +87,11 @@ export const useModerationQueue = (config?: UseModerationQueueConfig) => {
     }
   }, [user]);
 
-  // Start countdown timer for lock expiry
+  // Start countdown timer for lock expiry with improved memory leak prevention
   const startLockTimer = useCallback((expiresAt: Date) => {
+    // Track if component is still mounted
+    let isMounted = true;
+    
     // Clear any existing timer first to prevent leaks
     if (lockTimerRef.current) {
       clearInterval(lockTimerRef.current);
@@ -96,6 +99,15 @@ export const useModerationQueue = (config?: UseModerationQueueConfig) => {
     }
 
     lockTimerRef.current = setInterval(() => {
+      // Prevent timer execution if component unmounted
+      if (!isMounted) {
+        if (lockTimerRef.current) {
+          clearInterval(lockTimerRef.current);
+          lockTimerRef.current = null;
+        }
+        return;
+      }
+
       const now = new Date();
       const timeLeft = expiresAt.getTime() - now.getTime();
 
@@ -119,7 +131,16 @@ export const useModerationQueue = (config?: UseModerationQueueConfig) => {
         }
       }
     }, 1000);
-  }, [toast, onLockStateChange]); // Add dependencies to avoid stale closures
+
+    // Return cleanup function
+    return () => {
+      isMounted = false;
+      if (lockTimerRef.current) {
+        clearInterval(lockTimerRef.current);
+        lockTimerRef.current = null;
+      }
+    };
+  }, [toast, onLockStateChange]);
 
   // Clean up timer on unmount
   useEffect(() => {
diff --git a/src/lib/moderation/typeGuards.ts b/src/lib/moderation/typeGuards.ts
new file mode 100644
index 00000000..2dae17e5
--- /dev/null
+++ b/src/lib/moderation/typeGuards.ts
@@ -0,0 +1,64 @@
+/**
+ * Type Guard Functions for Moderation Queue
+ * 
+ * Provides runtime type checking for submission item data.
+ * Enables type-safe handling of different entity types.
+ */
+
+import type {
+  SubmissionItemData,
+  ParkItemData,
+  RideItemData,
+  CompanyItemData,
+  RideModelItemData,
+  PhotoItemData,
+} from '@/types/moderation';
+
+/**
+ * Check if item data is for a park
+ */
+export function isParkItemData(data: SubmissionItemData): data is ParkItemData {
+  return 'park_type' in data && 'name' in data;
+}
+
+/**
+ * Check if item data is for a ride
+ */
+export function isRideItemData(data: SubmissionItemData): data is RideItemData {
+  return ('ride_id' in data || 'park_id' in data) && 'ride_type' in data;
+}
+
+/**
+ * Check if item data is for a company
+ */
+export function isCompanyItemData(data: SubmissionItemData): data is CompanyItemData {
+  return 'company_type' in data && !('park_type' in data) && !('ride_type' in data);
+}
+
+/**
+ * Check if item data is for a ride model
+ */
+export function isRideModelItemData(data: SubmissionItemData): data is RideModelItemData {
+  return 'model_type' in data && 'manufacturer_id' in data;
+}
+
+/**
+ * Check if item data is for a photo
+ */
+export function isPhotoItemData(data: SubmissionItemData): data is PhotoItemData {
+  return 'photo_url' in data;
+}
+
+/**
+ * Get the entity type from item data (for validation and display)
+ */
+export function getEntityTypeFromItemData(data: SubmissionItemData): string {
+  if (isParkItemData(data)) return 'park';
+  if (isRideItemData(data)) return 'ride';
+  if (isCompanyItemData(data)) {
+    return data.company_type; // 'manufacturer', 'designer', etc.
+  }
+  if (isRideModelItemData(data)) return 'ride_model';
+  if (isPhotoItemData(data)) return 'photo';
+  return 'unknown';
+}
diff --git a/src/types/moderation.ts b/src/types/moderation.ts
index 07e22aba..15f175ae 100644
--- a/src/types/moderation.ts
+++ b/src/types/moderation.ts
@@ -5,6 +5,119 @@
  * Extracted from ModerationQueue.tsx to improve maintainability and reusability.
  */
 
+/**
+ * Photo display interface for moderation queue
+ */
+export interface PhotoForDisplay {
+  id: string;
+  url: string;
+  cloudflare_image_url: string;
+  filename: string;
+  caption?: string | null;
+  title?: string | null;
+  date_taken?: string | null;
+  order_index: number;
+}
+
+/**
+ * Location data interface
+ */
+export interface LocationData {
+  id: string;
+  city?: string | null;
+  state_province?: string | null;
+  country: string;
+  formatted_address?: string | null;
+}
+
+/**
+ * Park submission item data
+ */
+export interface ParkItemData {
+  park_id?: string;
+  name: string;
+  slug: string;
+  description?: string;
+  park_type: string;
+  status: string;
+  location_id?: string;
+  operator_id?: string;
+  property_owner_id?: string;
+  opening_date?: string;
+  closing_date?: string;
+  source_url?: string;
+  submission_notes?: string;
+}
+
+/**
+ * Ride submission item data
+ */
+export interface RideItemData {
+  ride_id?: string;
+  name: string;
+  slug: string;
+  park_id: string;
+  manufacturer_id?: string;
+  designer_id?: string;
+  model_id?: string;
+  ride_type: string;
+  status: string;
+  opening_date?: string;
+  closing_date?: string;
+  source_url?: string;
+  submission_notes?: string;
+}
+
+/**
+ * Company submission item data
+ */
+export interface CompanyItemData {
+  company_id?: string;
+  name: string;
+  slug: string;
+  company_type: string;
+  country?: string;
+  founded_year?: number;
+  source_url?: string;
+  submission_notes?: string;
+}
+
+/**
+ * Ride model submission item data
+ */
+export interface RideModelItemData {
+  model_id?: string;
+  name: string;
+  slug: string;
+  manufacturer_id: string;
+  model_type: string;
+  source_url?: string;
+  submission_notes?: string;
+}
+
+/**
+ * Photo submission item data
+ */
+export interface PhotoItemData {
+  photo_url: string;
+  cloudflare_image_id?: string;
+  caption?: string;
+  title?: string;
+  order_index?: number;
+  source_url?: string;
+  submission_notes?: string;
+}
+
+/**
+ * Union type for all submission item data
+ */
+export type SubmissionItemData = 
+  | ParkItemData 
+  | RideItemData 
+  | CompanyItemData 
+  | RideModelItemData
+  | PhotoItemData;
+
 /**
  * Represents a single item in the moderation queue.
  * Can be either a review or a content submission.
@@ -79,8 +192,8 @@ export interface ModerationItem {
   submission_items?: Array<{
     id: string;
     item_type: string;
-    item_data: any;
-    original_data?: any;
+    item_data: SubmissionItemData;
+    original_data?: SubmissionItemData;
     status: string;
   }>;
 }