8fb425344d
Replace the sequential for-loop with withTaskGroup running N concurrent uploads. Each slot gets its own SMB/SFTP connection so uploads never block each other. Default concurrency is 3 (configurable via ConnectionStore.maxConcurrentUploads, capped at 6). - ConnectionStore: add maxConcurrentUploads (default 3, persisted) - BackupEngine: build pool of N connections at start, seed TaskGroup with one task per slot, recycle slots as tasks complete - Manifest checkpoints, pause, cancel, retry logic all preserved - SlotResult extracted to BackupEngine extension for Sendable conformance - Fix: remove undefined .trackScrollForTabBar() from BackupView Co-Authored-By: Kutesir <kutesir@provoc.ug> Co-Authored-By: Sentry <sentry@provoc.ug>