Name diff options after the view that now uses them

Hunk defaults and wrapping no longer belong to a staging panel. Rename both
public keys with automatic migration, and remove panel-era English strings so
config, UI, schema, and generated docs describe the surviving interface.

Co-Authored-By: GitHub Copilot <copilot@github.com>

pkg/gui/controllers/helpers/diff_line_selection.go

@@ -70,7 +70,7 @@ func (self *DiffLineHelper) EstablishSelection(mainContext *context.MainContext,
 // there is nothing else to offer. Line by line it is simply the first change line on
 // screen. ok is false when the viewport shows no change at all.
 func (self *DiffLineHelper) changeToSelectOnScreen(view *gocui.View) (int, bool) {
-	if self.c.UserConfig().Gui.UseHunkModeInStagingView {
+	if self.c.UserConfig().Gui.UseHunkModeInDiffView {
 		return self.FirstChangeBlockInView(view)
 	}
 	return self.FirstChangeLineInView(view)
@@ -81,7 +81,7 @@ func (self *DiffLineHelper) changeToSelectOnScreen(view *gocui.View) (int, bool)
 // except over a file shown as one solid block of changes, where it would select the
 // whole file — see IsSingleHunkForWholeFile.
 func (self *DiffLineHelper) hunkModeApplies(view *gocui.View, changeViewLine int) bool {
-	return self.c.UserConfig().Gui.UseHunkModeInStagingView &&
+	return self.c.UserConfig().Gui.UseHunkModeInDiffView &&
 		!self.IsSingleHunkForWholeFile(view, changeViewLine)
 }
 

pkg/gui/controllers/helpers/mode_helper.go

@@ -71,7 +71,7 @@ func (self *ModeHelper) Statuses() []ModeStatus {
 				return self.withResetButton(self.c.Tr.BuildingPatch, style.FgYellow.SetBold())
 			},
 			CancelLabel: func() string {
-				return self.c.Tr.ExitCustomPatchBuilder
+				return self.c.Tr.ResetCustomPatch
 			},
 			Reset: self.customPatchHelper.Reset,
 		},