Add the Config view: edit and save the settings, applied without a restart

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/ui/form.go

@@ -51,9 +51,24 @@ func arrowNavigation(f *tview.Form, cancel func(), hooks *browseHooks) {
 		}
 		switch ev.Key() {
 		case tcell.KeyDown:
+			if pos == total-1 && hooks != nil && hooks.edge != nil && hooks.edge(true) {
+				return nil
+			}
 			f.SetFocus(min(pos+1, total-1))
 		case tcell.KeyUp:
+			if pos == 0 && hooks != nil && hooks.edge != nil && hooks.edge(false) {
+				return nil
+			}
 			f.SetFocus(max(pos-1, 0))
+		case tcell.KeyTab, tcell.KeyBacktab:
+			dir := 1
+			if ev.Key() == tcell.KeyBacktab {
+				dir = -1
+			}
+			if hooks != nil && hooks.tab != nil && hooks.tab(dir) {
+				return nil
+			}
+			return ev
 		case tcell.KeyLeft, tcell.KeyRight:
 			step := 1
 			if ev.Key() == tcell.KeyLeft {
@@ -118,6 +133,11 @@ func bindSearchNow(box *tview.Checkbox, searchable func() bool, blocked func())
 type browseHooks struct {
 	browse func(dd *tview.DropDown, index int) // the highlight moved to entry index
 	abort  func()                              // the list was closed without selecting
+	// edge is called when Down is pressed on the last field or Up on the first;
+	// it returns true if it moved the focus elsewhere.
+	edge func(down bool) bool
+	// tab is called for Tab (dir 1) and Shift+Tab (dir -1); true if handled.
+	tab func(dir int) bool
 }
 
 // browser mirrors the highlight of an open dropdown list, which tview does