Add IR remote control (LIRC) with a number-key content mapping

Adds a TCP client for lircd's classic protocol: play/pause/next/prev/
volume/mute map to the same intents every other front-end already
emits, and number keys 0-9 play an assigned album/audiobook from the
start or a podcast show's newest episode, resolved fresh on every
press. The mapping is configured in config.yml and editable from the
frontend: a small "Taste zuweisen" button on the play screen (or the
A+digit keyboard shortcut) opens a 10-key picker to assign whatever is
currently playing.

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

web/src/api/client.ts

@@ -1,6 +1,16 @@
 /** Every call the UI makes. Commands are fire-and-forget: the websocket reports back. */
 
-import type { Album, HaConfig, HaEntityState, PlayerState, Settings, TrackDetail } from "./types";
+import type {
+  Album,
+  HaConfig,
+  HaEntityState,
+  LircConfig,
+  PlayerState,
+  RemoteMapping,
+  RemoteSlotInput,
+  Settings,
+  TrackDetail,
+} from "./types";
 
 async function request<T>(path: string, init?: RequestInit): Promise<T> {
   const response = await fetch(`/api${path}`, {
@@ -29,6 +39,15 @@ async function fetchHaConfig(): Promise<HaConfig | null> {
   return (await response.json()) as HaConfig;
 }
 
+/** `null` means the IR remote isn't configured, not an error - same convention as
+ * `fetchHaConfig`. */
+async function fetchLircConfig(): Promise<LircConfig | null> {
+  const response = await fetch("/api/lirc");
+  if (response.status === 404) return null;
+  if (!response.ok) throw new Error(`GET /lirc failed: ${response.status}`);
+  return (await response.json()) as LircConfig;
+}
+
 /** `null` covers both "unknown to Home Assistant" and "Home Assistant unreachable
  * right now" (the backend answers the latter with a 502) - the room page treats a
  * device with no state the same way either way, rather than crashing on a poll. */
@@ -80,6 +99,11 @@ export const api = {
     post(`/ha/services/${domain}/${service}`, body),
 
   trackDetail: fetchTrackDetail,
+
+  lircConfig: fetchLircConfig,
+  remoteMapping: () => request<RemoteMapping>("/remote/mapping"),
+  saveRemoteMapping: (slots: Record<string, RemoteSlotInput>) =>
+    request<RemoteMapping>("/remote/mapping", { method: "PUT", body: JSON.stringify({ slots }) }),
 };
 
 export const coverUrl = (albumId: string) => `/api/albums/${albumId}/cover`;

web/src/api/types.ts

@@ -72,7 +72,7 @@ export interface PlayerState {
   /** Percent, 0..100. The device's configured range never leaves the backend. */
   volume: number;
   active_figure: string | null;
-  connected: { firmware: boolean; mqtt: boolean };
+  connected: { firmware: boolean; mqtt: boolean; lirc: boolean };
 }
 
 export interface Settings {
@@ -107,3 +107,31 @@ export interface HaEntityState {
   state: string;
   attributes: Record<string, unknown>;
 }
+
+export type RemoteTargetKind = "album" | "series";
+
+/** One number key (0-9) on the IR remote. "album": `target` is an `Album.id`, always
+ * started from track 0. "series": `target` is a podcast show name (`Album.series`),
+ * resolved to that show's newest episode fresh on every press. `resolved_album_id` is
+ * what it plays *right now* - `null` when the target no longer resolves (a moved
+ * album, an unknown show). Mirrors `RemoteSlotOut`. */
+export interface RemoteSlot {
+  digit: string;
+  target_kind: RemoteTargetKind;
+  target: string;
+  resolved_album_id: string | null;
+}
+
+export interface RemoteMapping {
+  slots: RemoteSlot[];
+}
+
+export interface RemoteSlotInput {
+  target_kind: RemoteTargetKind;
+  target: string;
+}
+
+/** Presence-only, like `HaConfig` - there is nothing secret in a host/port. */
+export interface LircConfig {
+  connected: boolean;
+}