enhance ImageWithFallback with retry, accessibility, loading, and tests

[Franker24]

This PR enhances the Figma ImageWithFallback component with improved accessibility, performance options, security compliance, and robust error-handling retry capabilities. It also adds a comprehensive suite of unit tests, achieving 100% test coverage.

Key Improvements

1. Robust Retry Logic

• Implemented a one-time retry mechanism when image loading fails.
• For non-data URLs, a cache-busting query parameter (?retry=1 or &retry=1) is automatically appended on the first failure to guarantee the browser initiates a new network request instead of reusing cached error states.
• Ensures no infinite loops by limiting the retry count to 1 before resolving to the fallback image.
• State (hasError and retryCount) is automatically reset when the src prop changes.

2. Enhanced Accessibility

• Fallback image now includes a descriptive aria-label="Error loading image".
• Uses a default alt text (alt="Image") when the prop is omitted to prevent screen readers from skipping the image or announcing missing alt tags.

3. Performance Boost

• Enabled loading="lazy" by default on normal image renders.
• Allows full customization/override of the loading behavior via props (e.g., loading="eager").

4. DOM Exposure Security

• Removed the old data-original-url attribute from the fallback image tag. Once the component switches to the fallback state, the original (possibly unsafe/private) source URL is completely unmounted and no longer exposed anywhere in the DOM.

5. High-Coverage Unit Tests

Created src/app/components/figma/ImageWithFallback.test.tsx covering all execution paths:

• Normal image rendering & parameter defaults
• Custom overrides (loading="eager")
• onLoad callback firing
• First-error retry & cache-buster injection verification
• Safe data URL retry validation
• Second-error fallback render
• Complete safety validation (no original src exposed in DOM during fallback)
• State reset on src changes

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Verification Results

Unit Tests

Ran Vitest checks:

pnpm test src/app/components/figma/ImageWithFallback.test.tsx

Closes #183 

[Jagadeeshftw]

the retry, accessibility, and loading improvements to ImageWithFallback plus the tests are a great robustness upgrade. rebased on latest main and dropped one unused import to keep the typecheck clean. thanks!