🧹 Remove unused upload.shared check in media upload route

[google-labs-jules]

🎯 What: Simplified the middleware usage for the /api/wp-upload-media POST endpoint in frontend/server.js by removing the redundant ternary operator upload.shared ? upload.single('file') : upload.single('file').
💡 Why: The ternary operator was evaluating to the exact same expression (upload.single('file')) on both branches. Removing it improves readability and reduces code complexity.
✅ Verification: Ran node server.js to ensure the Express application boots correctly and no syntax errors were introduced. Requested code review, which passed.
✨ Result: Cleaner, more maintainable code without modifying functionality.

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PR created automatically by Jules for task 15799129104605108352 started by @instituto-ops

[google-labs-jules]

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