Feature: Reset User Preferences/Layout/Settings (Global & Per-Area)

### Why
Allow user to "reset" all or part of their saved UI preferences, including layout (shell), theme, table state, etc. Useful if settings become corrupt or user wants to revert to defaults. Should be available as global and per-area, and expose via the persistence framework.

### Acceptance Criteria
- Provide UI affordance(s) for Reset: all and per-page/feature
- Reset mechanism fully clears appropriate storage keys (session/local)
- Confirmation dialog before reset (avoid accidental loss)
- Reset reverts to factory defaults as defined
- Unit/E2E or manual validation of reset in all affected screens
- Document API to call reset from code/testing

### Deliverables
- Reset action in UI (global, per-feature)
- Documentation of reset integration