Description

Refactored and simplified the speed calculation logic by calculating speed and ETA once using the total uploaded bytes instead of per file. The upload store was also streamlined into a leaner setup-style implementation with private helpers, a simplified data structure, and a unified TypeScript type for uploads. Some logic was moved to components to keep the store holding only data and logic that is shared. Upload progress updates now occur on a fixed 1-second interval to ensure consistent refresh rates. Additionally, some fixes were addressed: starting speed from the first measured value instead of zero for accurate initial reporting, suppressing error notifications for aborted uploads, and counting empty files or folders as 1 byte so their progress is properly tracked.

fixes #5339

Checklist

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