feat: v1.8.0 — new themes, queue toolbar, lightbox, i18n (fr/nl)

Themes:
- Add Poison (phosphor green on charcoal), Nucleo (warm brass light), Classic Winamp (LCD glow, Winamp yellow/orange) themes
- Overhaul Psychowave — refined deep violet, no longer WIP
- Reorganise ThemePicker into groups: Catppuccin, Nord, Retro, Tokyo Night, Psysonic Themes
- Add --volume-accent CSS var for per-theme volume slider colour override

Queue:
- Full toolbar redesign with centred round buttons (Shuffle/Save/Load/Clear/Gapless/Crossfade)
- Crossfade popover with 1–10 s range slider, right-aligned to avoid viewport overflow
- Queue header: title + count + duration inline in accent colour, close button removed
- Tech info (codec/bitrate) as frosted-glass overlay badge on cover art

UI:
- CoverLightbox shared component for album cover (AlbumHeader) and artist avatar (ArtistDetail)
- NowPlayingDropdown: separate spinning/loading state — button always clickable, icon spins 600 ms min
- Settings: "Experimental" badge on Crossfade and Gapless toggles
- Help page: 2-column grid layout, new Crossfade & Gapless Q&A entry, updated theme/language entries

i18n:
- Full French (fr) and Dutch (nl) translations across all namespaces
- Language selector sorted alphabetically (nl, en, fr, de)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/ConnectionIndicator.tsx

@@ -1,4 +1,5 @@
 import { useTranslation } from 'react-i18next';
+import { useNavigate } from 'react-router-dom';
 import { ConnectionStatus } from '../hooks/useConnectionStatus';
 
 interface Props {
@@ -9,17 +10,24 @@ interface Props {
 
 export default function ConnectionIndicator({ status, isLan, serverName }: Props) {
   const { t } = useTranslation();
+  const navigate = useNavigate();
 
   const label = isLan ? 'LAN' : t('connection.extern');
-  const title =
+  const tooltip =
     status === 'connected'
-      ? t('connection.connected')
+      ? t('connection.connectedTo', { server: serverName })
       : status === 'disconnected'
-      ? t('connection.disconnected')
+      ? t('connection.disconnectedFrom', { server: serverName })
       : t('connection.checking');
 
   return (
-    <div className="connection-indicator" data-tooltip={title} data-tooltip-pos="bottom">
+    <div
+      className="connection-indicator"
+      style={{ cursor: 'pointer' }}
+      onClick={() => navigate('/settings', { state: { tab: 'server' } })}
+      data-tooltip={tooltip}
+      data-tooltip-pos="bottom"
+    >
       <div className={`connection-led connection-led--${status}`} />
       <div className="connection-meta">
         <span className="connection-type">{label}</span>