feat: v0.2.0 — UI rebuilt to WordPress admin standards

v0.1.0 worked but felt like a third-party React widget bolted on
top of WordPress. v0.2.0 makes the player visually native to the
WP admin: postbox container, standard Play/Pause button with text
label, admin-colour-scheme aware accents, dashboard widget no
longer renders a card inside a card.

CHANGES
- inc/admin-page.php: main page now wraps the player in a
  .postbox > .postbox-header (with h2.hndle) > .inside structure.
  Custom rounded card / shadow stripped.
- inc/dashboard-widget.php: bare .radio-player content; WP already
  wraps dashboard widgets in a postbox, was double-card before.
- inc/about.php: version-history card promotes v0.2.0 to latest,
  demotes v0.1.0.
- assets/css/radio.css: rewrite. Strip custom shadows + oversized
  typography. Adopt WP body-text defaults. Use
  var(--wp-admin-theme-color, #2271b1) for volume-slider accent +
  link colours so the plugin picks up whichever admin colour
  scheme the user has chosen. About-page cards now use the
  postbox-style gray header + 1px border pattern.
- assets/js/radio.js: setPlayIcon() also flips the visible text
  label ("Play" ↔ "Pause"), not just the icon class. mirrorSelection()
  also updates the [data-radio-genre] element so the genre label
  stays in sync across surfaces.
- radio.php: Version: 0.1.0 -> 0.2.0; BUDDY_VERSION constant
  bumped likewise.
- CHANGELOG.md: new [0.2.0] entry explaining the visual overhaul.

NET EFFECT
- Same 44 stations, same audio path, same persistence, same
  updater, same AJAX endpoint. Pure visual change.
- The plugin now looks like part of WordPress admin instead of a
  guest widget.
- Closer to WP.org submission criteria — plugin reviewers look
  for native-styled plugins.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

inc/dashboard-widget.php

@@ -2,9 +2,9 @@
 /**
  * Radio — dashboard widget.
  *
- * The compact mini-player on WP Admin → Dashboard. Same HTML structure
- * as the main admin page but smaller, so the assets/js/radio.js can
- * bind to whichever surface the user opens first.
+ * The compact mini-player on WP Admin → Dashboard. WordPress wraps
+ * dashboard widgets in a .postbox automatically, so we render bare
+ * content here — no nested card styling.
  */
 
 if ( ! defined( 'ABSPATH' ) ) { exit; }
@@ -31,21 +31,25 @@ function radio_render_dashboard_widget() {
     $station  = radio_find_station( $state['station_id'] );
     $stations = radio_get_stations_grouped();
     ?>
-    <div class="radio-player radio-player--widget" data-radio-surface="widget">
+    <div class="radio-player" data-radio-surface="widget">
+
         <div class="radio-player__now">
-            <div class="radio-player__label"><?php esc_html_e( 'Now Playing', 'radio' ); ?></div>
-            <div class="radio-player__station-name" data-radio-name><?php echo esc_html( $station['name'] ); ?></div>
-            <div class="radio-player__station-desc" data-radio-desc><?php echo esc_html( $station['description'] ); ?></div>
+            <span class="radio-player__label"><?php esc_html_e( 'Now Playing', 'radio' ); ?></span>
+            <span class="radio-player__station-name" data-radio-name><?php echo esc_html( $station['name'] ); ?></span>
+            <span class="radio-player__station-genre" data-radio-genre><?php echo esc_html( $station['genre'] ); ?></span>
+            <p class="radio-player__station-desc" data-radio-desc><?php echo esc_html( $station['description'] ); ?></p>
         </div>
 
         <div class="radio-player__controls">
-            <button type="button" class="radio-player__play button button-primary" data-radio-play title="<?php esc_attr_e( 'Play', 'radio' ); ?>">
-                <span class="dashicons dashicons-controls-play"></span>
+            <button type="button" class="button button-primary radio-player__play" data-radio-play>
+                <span class="dashicons dashicons-controls-play" aria-hidden="true"></span>
+                <span data-radio-play-label><?php esc_html_e( 'Play', 'radio' ); ?></span>
             </button>
 
             <div class="radio-player__volume">
-                <span class="dashicons dashicons-controls-volumeon"></span>
+                <span class="dashicons dashicons-controls-volumeon" aria-hidden="true"></span>
                 <input type="range" min="0" max="100" value="<?php echo esc_attr( (int) round( $state['volume'] * 100 ) ); ?>" data-radio-volume aria-label="<?php esc_attr_e( 'Volume', 'radio' ); ?>">
+                <span class="radio-player__volume-pct" data-radio-volume-pct><?php echo esc_html( (int) round( $state['volume'] * 100 ) ); ?>%</span>
             </div>
         </div>
 
@@ -57,7 +61,7 @@ function radio_render_dashboard_widget() {
                 ?>
                     <optgroup label="<?php echo esc_attr( $genre ); ?>">
                         <?php foreach ( $entries as $entry ) : ?>
-                            <option value="<?php echo esc_attr( $entry['id'] ); ?>" data-url="<?php echo esc_attr( $entry['url'] ); ?>" data-desc="<?php echo esc_attr( $entry['description'] ); ?>" <?php selected( $entry['id'], $state['station_id'] ); ?>>
+                            <option value="<?php echo esc_attr( $entry['id'] ); ?>" data-url="<?php echo esc_attr( $entry['url'] ); ?>" data-desc="<?php echo esc_attr( $entry['description'] ); ?>" data-genre="<?php echo esc_attr( $entry['genre'] ); ?>" <?php selected( $entry['id'], $state['station_id'] ); ?>>
                                 <?php echo esc_html( $entry['name'] ); ?>
                             </option>
                         <?php endforeach; ?>
@@ -72,7 +76,6 @@ function radio_render_dashboard_widget() {
 
         <p class="radio-player__credit">
             <?php
-            /* translators: %s = SomaFM link */
             printf(
                 wp_kses(
                     /* translators: %s = link to somafm.com */