Work Item: Move repository and source management into route-based content

[ksamaschke]

Deliverable

Relocate repository and source-management workflows from the Settings tab model into the desktop shell’s route-based main-window content.

## Dependencies
- Parent story: #204.

• Blocked by Work Item: Replace tab navigation with persistent sidebar routes #215.

  Completion evidence

  • Route placement notes for repository and source management.

• Screens or descriptions showing source operations in route content.

• Linked TDD items for tests and implementation.

  Acceptance criteria

  • Repository and source operations no longer depend on a Settings tab.

• Source management is represented in route content appropriate for the desktop shell.

• The placement supports desktop list/detail workflow patterns.

  Parent: Story: Workspace navigation and content architecture #204