[Enhancement] Bucket: Improve file existence validation flow based on selected destination path

[MarunNexit]

[Enhancement] Bucket: Improve file existence validation flow based on selected destination path

Description:

Currently, file existence validation is triggered immediately after selecting a file for upload, based on the initial (default) bucket location.

To improve usability and make the validation logic more intuitive, the validation flow should be adjusted so that the system checks for file conflicts only after the user selects the destination path.

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Current Behavior:

• After selecting a file for upload, the system immediately performs a file existence check in the initial bucket location.
• A warning is displayed before the user has chosen the final upload path.
• Validation is not strictly tied to the user’s selected destination folder.

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Improvement:

Update the validation sequence to follow this flow:

1. User selects a file for upload.
2. User selects the destination path.
3. System checks whether a file with the same name exists in the selected path.
4. Warning is displayed only if a conflict exists in that specific folder.

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Expected Outcome:

• Validation becomes context-aware and tied to the final destination.
• Warnings are displayed only when relevant.
• Reduced confusion and improved UX.
• Prevents unintended overwrites by ensuring conflict checks are performed against the actual target path.