🧹 Use early return for rootViewController in openLookAround

[esenmx]

🎯 What: Simplified host rootViewController resolution in openLookAround by merging the variable declaration with guard let.
💡 Why: Eliminates extra variable declaration and avoids redundant checking, improving readability and maintainability.
✅ Verification: Verified code structure and executed full test suite (flutter test, flutter analyze, dart format .).
✨ Result: Clean, idiomatic Swift code without functional changes.

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PR created automatically by Jules for task 2670158294578776982 started by @esenmx

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