Add reset all workspaces with backup restore

[tonythethompson]

QuickShell includes a reset-all workflow that clears the workspace store while preserving a backup for recovery. The Raycast extension should keep that management action so users can recover from a bad workspace set without manually deleting files.

Acceptance criteria:

• A settings or management action can reset all workspaces.
• Reset creates or preserves a backup snapshot before clearing data.
• The cleared state is recoverable from the backup.
• The user sees a clear confirmation before the reset happens.

[tonythethompson]

Audit against current code (QuickShell.Raycast): NOT YET IMPLEMENTED.
No reset-all-with-backup management action found in storage/lib/UI. Backlog item.

[tonythethompson]

Audit correction (re-checked against the .NET main project, the actual QuickShell):

.NET HAS this: QuickShell/Commands/ResetTransferCommands.cs resets all workspaces while keeping a backup for recovery. Raycast port: no reset-all-with-backup action. Stays open (Raycast gap).

[tonythethompson]

Re-audit (2026-07-22)

Verdict: NOT DONE (Raycast gap). Remains open.

CmdPal/Core still has reset-all with backup (ResetTransferCommands / ShortcutRepository.ResetAll). Raycast settings only expose Export/Import/Undo/Redo; no reset-all + backup restore action yet.