Add automatic backup/restore to HA server (survives cache clear)

Uses Home Assistant's frontend/set_user_data WebSocket API to
automatically save favorites and custom stations to the HA server.
On card load, if localStorage is empty (cache was cleared), data
is automatically restored from the server backup.

- Main card: auto-saves on every favorite/custom station change
- Both cards: auto-restore on first hass connection if cache empty
- Zero configuration needed - works out of the box
- Manual JSON backup/restore buttons still available as fallback
- Data stored per-user in HA's .storage/frontend.user_data

https://claude.ai/code/session_01PHdKi2HPbQoM3EevzgSQFc

Author: claude

radio-browser-card.js

@@ -69,6 +69,11 @@ class RadioBrowserCard extends HTMLElement {
       }
     }
 
+    // On first hass connection, auto-restore from HA server if cache was cleared
+    if (!oldHass && hass) {
+      this._autoRestoreFromHA();
+    }
+
     if (!oldHass || Object.keys(oldHass.states).length !== Object.keys(hass.states).length) {
       this.updateMediaPlayers();
     }
@@ -93,6 +98,7 @@ class RadioBrowserCard extends HTMLElement {
   saveFavorites() {
     try {
       localStorage.setItem('radio_favorites', JSON.stringify(this._favorites));
+      this._autoBackupToHA();
     } catch (e) {
       console.error('Error saving favorites:', e);
     }
@@ -111,11 +117,66 @@ class RadioBrowserCard extends HTMLElement {
   saveCustomStations() {
     try {
       localStorage.setItem('radio_custom_stations', JSON.stringify(this._customStations));
+      this._autoBackupToHA();
     } catch (e) {
       console.error('Error saving custom stations:', e);
     }
   }
 
+  // Auto-backup to Home Assistant server (survives cache clear)
+  async _autoBackupToHA() {
+    if (!this._hass) return;
+    try {
+      await this._hass.callWS({
+        type: 'frontend/set_user_data',
+        key: 'radio_browser_backup',
+        value: {
+          favorites: this._favorites,
+          custom_stations: this._customStations,
+          timestamp: Date.now()
+        }
+      });
+      console.log('Auto-backup to HA server OK');
+    } catch (e) {
+      console.log('Auto-backup to HA server failed:', e);
+    }
+  }
+
+  // Auto-restore from Home Assistant server (after cache clear)
+  async _autoRestoreFromHA() {
+    if (!this._hass) return;
+    try {
+      const result = await this._hass.callWS({
+        type: 'frontend/get_user_data',
+        key: 'radio_browser_backup'
+      });
+      if (!result || !result.value) return;
+
+      const data = result.value;
+      const localFavs = localStorage.getItem('radio_favorites');
+      const localCustom = localStorage.getItem('radio_custom_stations');
+      const hasLocalData = (localFavs && JSON.parse(localFavs).length > 0) ||
+                           (localCustom && JSON.parse(localCustom).length > 0);
+
+      // Only restore if localStorage is empty (cache was cleared) and server has data
+      if (!hasLocalData && (data.favorites?.length > 0 || data.custom_stations?.length > 0)) {
+        console.log('Cache cleared detected - restoring from HA server backup...');
+        if (data.favorites?.length > 0) {
+          this._favorites = data.favorites;
+          localStorage.setItem('radio_favorites', JSON.stringify(data.favorites));
+        }
+        if (data.custom_stations?.length > 0) {
+          this._customStations = data.custom_stations;
+          localStorage.setItem('radio_custom_stations', JSON.stringify(data.custom_stations));
+        }
+        console.log(`Restored: ${data.favorites?.length || 0} favorites, ${data.custom_stations?.length || 0} custom stations`);
+        this.updatePlaylist();
+      }
+    } catch (e) {
+      console.log('Auto-restore from HA server not available:', e);
+    }
+  }
+
   // YouTube URL handling
   parseYouTubeUrl(url) {
     // Support various YouTube URL formats
@@ -2600,6 +2661,11 @@ class RadioBrowserCardCompact extends HTMLElement {
     const oldHass = this._hass;
     this._hass = hass;
 
+    // On first hass connection, auto-restore from HA server if cache was cleared
+    if (!oldHass && hass) {
+      this._autoRestoreFromHA();
+    }
+
     if (!oldHass || Object.keys(oldHass.states).length !== Object.keys(hass.states).length) {
       this._updateMediaPlayers();
     }
@@ -2638,6 +2704,37 @@ class RadioBrowserCardCompact extends HTMLElement {
     return all;
   }
 
+  // Auto-restore from Home Assistant server (after cache clear)
+  async _autoRestoreFromHA() {
+    if (!this._hass) return;
+    try {
+      const result = await this._hass.callWS({
+        type: 'frontend/get_user_data',
+        key: 'radio_browser_backup'
+      });
+      if (!result || !result.value) return;
+
+      const data = result.value;
+      const localFavs = localStorage.getItem('radio_favorites');
+      const localCustom = localStorage.getItem('radio_custom_stations');
+      const hasLocalData = (localFavs && JSON.parse(localFavs).length > 0) ||
+                           (localCustom && JSON.parse(localCustom).length > 0);
+
+      if (!hasLocalData && (data.favorites?.length > 0 || data.custom_stations?.length > 0)) {
+        console.log('Compact card: Restoring from HA server backup...');
+        if (data.favorites?.length > 0) {
+          localStorage.setItem('radio_favorites', JSON.stringify(data.favorites));
+        }
+        if (data.custom_stations?.length > 0) {
+          localStorage.setItem('radio_custom_stations', JSON.stringify(data.custom_stations));
+        }
+        this._updateStationSelect();
+      }
+    } catch (e) {
+      console.log('Compact card: Auto-restore not available:', e);
+    }
+  }
+
   // --- State persistence ---
   _saveState() {
     try {