AppSettings Structure

AppSettings is split into partial files by settings responsibility. Keep AppSettings.cs focused on data fields and default values.

File Map

File	Responsibility
`Models/AppSettings.cs`	`QuickPasteEntry`, core settings fields, the operation-state toggle/session store owner, file-jump settings fields, popup sizing fields, batch settings fields, recent-folder data fields, and exclusion app fields.
`Models/AppSettings.RecentFolders.cs`	Recent file-dialog folder confirmation, insertion, normalization, app install-directory guard, and removal.
`Models/AppSettings.ExplorerQuickFind.cs`	Explorer quick-find and file-jump Everything feature settings fields.
`Models/AppSettings.Display.cs`	Hotkey display-name properties and virtual-key formatting.
`Models/AppSettings.Normalize.cs`	Runtime normalization/default repair for popup sizes, page keys, and star toggle keys.
`Models/AppSettings.Persistence.cs`	Settings file locations, load path, legacy settings migration, and recent-folder migration.
`Models/AppSettings.Save.cs`	Debounced async save, synchronous save, and pending-save flush.
`Models/AppSettings.Copy.cs`	Shallow copy used for debounced save snapshots.

Add new persisted setting fields to AppSettings.cs or the closest feature-field partial.
Keep load-time compatibility fixes in Persistence.
Keep range/default repair in Normalize.
Keep save scheduling and file writes in Save.
Keep display-only formatting in Display.