feat: add repeat advanced argument for playlist end behaviour

Add RepeatOff/RepeatAll/RepeatOne constants and a Repeat field to
PlaylistArgs (oneof=off all one). Add IsRepeatAll/IsRepeatOne helpers
mirroring IsModeShuffle. The existing mode=shuffle arg is unchanged.

Author: wizzomafizzo

advargs.go

@@ -31,3 +31,13 @@ func IsActionRun(action string) bool {
 func IsModeShuffle(mode string) bool {
 	return strings.EqualFold(mode, ModeShuffle)
 }
+
+// IsRepeatAll returns true if the repeat value is "all" (case-insensitive).
+func IsRepeatAll(repeat string) bool {
+	return strings.EqualFold(repeat, RepeatAll)
+}
+
+// IsRepeatOne returns true if the repeat value is "one" (case-insensitive).
+func IsRepeatOne(repeat string) bool {
+	return strings.EqualFold(repeat, RepeatOne)
+}

types.go

@@ -47,6 +47,7 @@ const (
 	KeySlot           Key = "slot"
 	KeyTags           Key = "tags"
 	KeyMode           Key = "mode"
+	KeyRepeat         Key = "repeat"
 	KeyName           Key = "name"
 	KeyPreNotice      Key = "pre_notice"
 	KeyHidden         Key = "hidden"
@@ -66,6 +67,16 @@ const (
 	ModeShuffle = "shuffle"
 )
 
+// Repeat values for the repeat advanced argument.
+const (
+	// RepeatOff stops playback at the end of the playlist (default).
+	RepeatOff = "off"
+	// RepeatAll loops the whole playlist back to the start when it ends.
+	RepeatAll = "all"
+	// RepeatOne repeats the current track indefinitely.
+	RepeatOne = "one"
+)
+
 // GlobalArgs contains advanced arguments available to all commands.
 type GlobalArgs struct {
 	// When controls conditional execution. If non-empty and falsy, command is skipped.
@@ -164,6 +175,8 @@ type PlaylistArgs struct {
 	GlobalArgs
 	// Mode controls playlist behavior (e.g., "shuffle").
 	Mode string `advarg:"mode" validate:"omitempty,oneof=shuffle"`
+	// Repeat controls end-of-playlist behaviour: off (default), all (loop playlist), one (repeat track).
+	Repeat string `advarg:"repeat" validate:"omitempty,oneof=off all one"`
 	// Slot selects the media slot for playlist routing.
 	Slot string `advarg:"slot"`
 }