Improve component stability and user experience with safety checks

Implement robust error handling, safety checks for data structures, and state management improvements across various components to prevent runtime errors and enhance user experience.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: a71e826a-1d38-4b6e-a34f-fbf5ba1f1b25
Replit-Commit-Checkpoint-Type: intermediate_checkpoint

attached_assets/Pasted--Critical-Issues-1-Hot-Module-Reload-HMR-Failures-Your-browser-console-shows-HMR-errors-for-sev-1759950616776_1759950616777.txt

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+🔴 Critical Issues
+1. Hot Module Reload (HMR) Failures
+Your browser console shows HMR errors for several components:
+
+ManufacturerRides.tsx and ManufacturerModels.tsx
+Version-related components (VersionIndicator, VersionComparisonDialog, EntityVersionHistory)
+Impact: During development, changes to these files won't refresh automatically, requiring full page reloads.
+
+2. Fast Refresh Incompatibility
+Two exports are breaking React Fast Refresh:
+
+useSidebar in src/components/ui/sidebar.tsx
+uploadPendingImages in src/components/upload/EntityMultiImageUploader.tsx
+Impact: Components using these will cause full page reloads on changes instead of hot updates.
+
+⚠️ High Priority Issues
+3. Potential Race Conditions
+useEntityVersions hook: Uses a request counter but could still have timing issues when multiple requests are in flight
+useModerationQueue hook: Lacks explicit request cancellation, could show stale data if network is slow
+Impact: Users might see outdated information or experience data inconsistencies.
+
+4. Memory Leaks
+PhotoUpload component: Object URLs might not be revoked if upload errors occur
+useEntityVersions hook: Supabase realtime subscriptions might not cleanup properly on unmount
+useAuth hook: Timeouts for Novu updates might not be cleared when component unmounts
+Impact: Memory usage grows over time, eventually slowing down or crashing the browser.
+
+5. Missing Null/Undefined Safety Checks
+PhotoModal: Accessing currentPhoto without checking if photos array is empty
+EntityHistoryTimeline: Accessing event config without verifying it exists
+useEntityVersions: Assumes Supabase data is always an array
+EntityEditPreview: Accessing nested image data without structure validation
+Impact: Runtime errors that crash components when data is missing.
+
+🟡 Medium Priority Issues
+6. Inconsistent Error Handling
+Error handling varies across components:
+
+Some use console.error() (silent for users)
+Others use toast.error() (visible notifications)
+File upload errors don't show which specific file failed
+Impact: Users don't always know when something went wrong.
+
+7. State Management Issues
+useSearch hook: Uses JSON.stringify() for memoization which fails with functions/Symbols
+AutocompleteSearch: Search dropdown state not properly tied to loading state
+EntityEditPreview: Deep object comparison issues for detecting changes