Landscape orientation, redesigned web UI, rotation on/off + minutes, weather by city name

- Panel is mounted sideways: render landscape (600x400), rotate to the
  panel's native portrait orientation right before writing to hardware.
- Web UI: card-based layout, dark mode, active nav highlighting, save
  confirmation toasts, error banners.
- Rotation: separate enabled/disabled toggle (off pins to the first screen
  in the list) and the interval is now in minutes instead of raw seconds.
  Migrates existing config.json from the old interval_seconds field.
- Weather: type a city name instead of hunting down coordinates, resolved
  via Open-Meteo's free geocoding API. Manual lat/long still available as
  a fallback.

web/templates/index.html

@@ -2,24 +2,40 @@
 {% block content %}
 <h1>Status</h1>
 
-<img class="preview" src="{{ url_for('static', filename='preview.png') }}?t={{ status.last_render_at }}" alt="preview">
-
-<div class="status-grid">
-  <div>Current screen</div><div>{{ status.current_screen or "-" }}</div>
-  <div>Last render</div><div>{{ status.last_render_at or "-" }}</div>
-  <div>Last panel write</div><div>{{ status.last_display_write_at or "-" }}</div>
-  <div>Navidrome priority</div><div>{{ "on" if navidrome_priority else "off" }}</div>
-  <div>Rotation</div><div>{{ rotation.screens | join(" → ") }} (every {{ rotation.interval_seconds }}s)</div>
+<div class="card">
+  <div class="section-label">Preview</div>
+  <div class="preview-wrap">
+    <img class="preview" src="{{ url_for('static', filename='preview.png') }}?t={{ status.last_render_at }}" alt="preview">
+  </div>
 </div>
 
-<div class="actions">
-  <form class="inline" method="post" action="{{ url_for('refresh_now') }}">
-    <button type="submit">Refresh now</button>
-  </form>
-  {% for screen_id, screen in screens.items() %}
-  <form class="inline" method="post" action="{{ url_for('switch_now', screen_id=screen_id) }}">
-    <button class="secondary" type="submit">Show {{ screen.display_name }}</button>
-  </form>
-  {% endfor %}
+<div class="card">
+  <div class="section-label">Overview</div>
+  <dl class="status-grid">
+    <dt>Current screen</dt><dd>{{ status.current_screen or "-" }}</dd>
+    <dt>Last render</dt><dd>{{ status.last_render_at or "-" }}</dd>
+    <dt>Last panel write</dt><dd>{{ status.last_display_write_at or "-" }}</dd>
+    <dt>Navidrome priority</dt>
+    <dd><span class="badge {{ 'on' if navidrome_priority else 'off' }}">{{ "on" if navidrome_priority else "off" }}</span></dd>
+    <dt>Rotation</dt>
+    <dd>
+      <span class="badge {{ 'on' if rotation.enabled else 'off' }}">{{ "on" if rotation.enabled else "off" }}</span>
+      {{ rotation.screens | join(" → ") }} (every {{ rotation.interval_minutes }} min)
+    </dd>
+  </dl>
+</div>
+
+<div class="card">
+  <div class="section-label">Actions</div>
+  <div class="actions">
+    <form class="inline" method="post" action="{{ url_for('refresh_now') }}">
+      <button type="submit">Refresh now</button>
+    </form>
+    {% for screen_id, screen in screens.items() %}
+    <form class="inline" method="post" action="{{ url_for('switch_now', screen_id=screen_id) }}">
+      <button class="secondary" type="submit">Show {{ screen.display_name }}</button>
+    </form>
+    {% endfor %}
+  </div>
 </div>
 {% endblock %}