Work Item: Redesign Workspace, Sources, Hooks, and Reports as desktop list/detail flows

[ksamaschke]

Deliverable

Turn the four desktop routes into desktop-style list/detail or focused workflow content instead of dashboard panels and summary cards.

## Dependencies
- Parent story: #204.

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

• Blocked by Work Item: Move repository and source management into route-based content #216.

  Completion evidence

  • Route-by-route content model describing list/detail, selection, and empty states.

• Screens or references showing desktop workflow patterns in each route.

• Linked TDD items for tests and implementation.

  Acceptance criteria

  • Workspace, Sources, Hooks, and Reports each have desktop-first content architecture.

• Primary interactions use focused list/detail or task flows instead of a dashboard card matrix.

• The main window reads as an operating workspace rather than a generalized dashboard.

  Parent: Story: Workspace navigation and content architecture #204