feat(remote-sync): refactor remote sync process

[egalvis27]

What is Changed / Added

---

This PR refactors the remote-sync module to make the flow more explicit, more functional, and easier to maintain.

The previous implementation was centered around a large stateful manager-like structure with multiple responsibilities mixed together. This change breaks that logic into smaller focused modules, clarifies the runtime orchestration layer, and reduces cross-layer coupling between context and apps/main.

What Changed

Remote sync controller refactor

• Reworked the remote sync orchestration into a dedicated remote-sync-controller module.
• Split controller responsibilities into smaller units such as:
  • controller state creation
  • status updates
  • aggregated sync status checks
  • reset logic
  • file sync orchestration
  • folder sync orchestration
  • start flow orchestration
• Simplified the controller API by removing unused surface such as localIsSynced.
• Updated the controller so runtime dependencies are passed only when startRemoteSync is executed, instead of being stored unnecessarily in the controller factory.

Error handling cleanup

• Replaced the previous class-based remote sync error handler with a functional implementation.
• Extracted error classification into a dedicated pure helper.
• Kept issue creation and logging behavior explicit while reducing branching and duplication.

Contract and boundary cleanup

• Introduced an explicit remote sync contract for the data returned to the context layer.
• Added DTO mapping at the application boundary instead of leaking database/entity shapes outside the main process runtime layer.
• Removed the direct context -> apps/main/remote-sync/service dependency by routing access through a shared remote sync service contract.
• Updated consumers such as the SQLite remote items generator and the file-overridden subscriber to use that shared boundary.

Naming and structure improvements

• Replaced legacy manager naming with controller naming across the remote sync slice.
• Removed obsolete files and renamed test coverage to match the current module structure.
• Added focused tests for the newly extracted controller helpers so the new file structure is reflected in the test layout.

Behavior fixes

• Fixed the folder sync pagination path so folder sync uses its own configured fetch limit instead of the file limit.
• Fixed a type mismatch in SQLiteRemoteItemsGenerator when mapping nullable DTO file types into ServerFile.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
90.2% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud