refactor(smartplaylist): remove unused 'value' field and clarify 'random' usage

Signed-off-by: Deluan <deluan@navidrome.org>

model/criteria/fields.go

@@ -88,8 +88,8 @@ var fieldMap = map[string]FieldInfo{
 	// Backward compatibility: albumtype is an alias for the releasetype tag.
 	"albumtype": {Alias: "releasetype", IsTag: true},
 
+	// Pseudo-field for random sorting
 	"random": {},
-	"value":  {},
 }
 
 // AllFieldNames returns the names of all registered criteria fields.

model/criteria/fields_test.go

@@ -22,13 +22,6 @@ var _ = Describe("fields", func() {
 			gomega.Expect(field.IsTag).To(gomega.BeTrue())
 		})
 
-		It("finds special fields", func() {
-			field, ok := LookupField("value")
-
-			gomega.Expect(ok).To(gomega.BeTrue())
-			gomega.Expect(field.Name()).To(gomega.Equal("value"))
-		})
-
 		It("finds registered tag names", func() {
 			AddTagNames([]string{"task3_mood"})
 

persistence/criteria_sql.go

@@ -117,7 +117,6 @@ var smartPlaylistFields = map[string]smartPlaylistField{
 	"rgtrackpeak":          {expr: "media_file.rg_track_peak"},
 	"library_id":           {expr: "media_file.library_id"},
 	"random":               {order: "random()"},
-	"value":                {expr: "value"},
 }
 
 func (c smartPlaylistCriteria) Where() (squirrel.Sqlizer, error) {