[MS-1317] Sync revamp: part 4

[alex-vt]

JIRA ticket
Will be released in: 2026.2.0

Boundaries for the changes - what's intentionally out of scope:

• WorkManager and workers. This is already the optimal foundation for sync - both foreground and background.
• SyncInfoViewModel. Already observes sync state.
• UI/UX. Nothing visually new.

Notable changes

• (Phase 1) (Done) SyncOrchestrator.observeSyncState implementation.
• (Phase 2) (Done) SyncOrchestrator.execute implementation.
• (Phase 3) (Done) SyncOrchestrator.execute cleanup (a lot of call sites involved).
• (Phase 4) (This) Reforming the remainder of the EventSyncManager into more cohesive repository & narrowly scoped usecases.
• (Phase 5) (Up next) Simplifying the SyncInfoUseCase.

Additional work checklist

• Effect on other features and security has been considered
• Design document marked as "In development" (if applicable)
• External (Gitbook) and internal (Confluence) Documentation is up to date (or ticket created)
• Test cases in Testiny are up to date (or ticket created)
• Other teams notified about the changes (if applicable)