Keep an empty name meaning "use Home Assistant's name"

formatEntityName returns any string it is given verbatim, the empty one
included, so `name: ''` blanked the label where it previously fell through
to the friendly name. It now reaches the formatter as undefined.

Also drops `parent_device` from the accepted name parts. It only landed in
the frontend on 2026-09-10 and is in no release yet, so under the 2026.4
gate it was silently ignored.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

README.md

@@ -174,7 +174,7 @@ name:
   - type: entity
 ```
 
-Available part types are `entity`, `device`, `parent_device`, `area`, `floor`, and
+Available part types are `entity`, `device`, `area`, `floor`, and
 `text` (a literal, written as `{type: text, text: 'Alarm'}`). Parts that resolve to
 nothing are dropped. A plain string `name` keeps working exactly as before, and the
 visual editor offers both modes on Home Assistant 2025.11 and later.

src/entity-name.ts

@@ -43,6 +43,11 @@ export function computeEntityName(
   stateObj: HassEntity | undefined,
   name: EntityName | undefined,
 ): string | undefined {
+  // A configured empty name has always meant "use Home Assistant's name", but
+  // formatEntityName returns any string verbatim - including the empty one, which
+  // would blank the label. Normalise it to undefined so the formatter composes.
+  if (name === '') name = undefined;
+
   const configuredName = typeof name === 'string' ? name : undefined;
 
   if (!stateObj) {

src/types.ts

@@ -20,7 +20,7 @@ export interface TimePickerCardConfig extends LovelaceCardConfig {
 export type EntityName = string | EntityNameItem | EntityNameItem[];
 
 export type EntityNameItem =
-  | { type: 'entity' | 'device' | 'parent_device' | 'area' | 'floor' }
+  | { type: 'entity' | 'device' | 'area' | 'floor' }
   | { type: 'text'; text: string };
 
 export type HourMode = 12 | 24 | undefined;