fix: ffmpeg/yt-dlp/tz in image, UID 1000, reactive accent store

- runtime: use node user (uid=1000, gid=1000) instead of custom tonemark uid=1001
- add ffmpeg and yt-dlp to runtime image (required by audio pipeline)
- add tzdata, set TZ=Europe/Zurich
- +page.svelte: replace hardcoded ACCENT constant with $derived($accent.value)
  so the home page reacts to accent store changes from Settings

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Dockerfile

@@ -21,21 +21,25 @@ FROM node:22-alpine AS runtime
 
 WORKDIR /app
 
-# Non-root user for security
-RUN addgroup -g 1001 tonemark && \
-    adduser -D -u 1001 -G tonemark tonemark
+# Runtime tools + timezone data
+RUN apk add --no-cache ffmpeg tzdata && \
+    wget -qO /usr/local/bin/yt-dlp \
+      https://github.com/yt-dlp/yt-dlp/releases/latest/download/yt-dlp && \
+    chmod +x /usr/local/bin/yt-dlp
 
 # Copy built output and production node_modules
-COPY --from=builder --chown=tonemark:tonemark /app/build ./build
-COPY --from=builder --chown=tonemark:tonemark /app/node_modules ./node_modules
-COPY --from=builder --chown=tonemark:tonemark /app/package.json ./
+# node:22-alpine ships with user node (uid=1000, gid=1000)
+COPY --from=builder --chown=node:node /app/build ./build
+COPY --from=builder --chown=node:node /app/node_modules ./node_modules
+COPY --from=builder --chown=node:node /app/package.json ./
 
-USER tonemark
+USER node
 
 EXPOSE 3000
 
 ENV NODE_ENV=production \
     PORT=3000 \
-    HOST=0.0.0.0
+    HOST=0.0.0.0 \
+    TZ=Europe/Zurich
 
 CMD ["node", "build/index.js"]

src/routes/+page.svelte

@@ -4,8 +4,9 @@
 	import SourceIcon from '$lib/components/SourceIcon.svelte';
 	import Waveform from '$lib/components/Waveform.svelte';
 	import RecordButton from '$lib/components/RecordButton.svelte';
+	import { accent } from '$lib/accent.js';
 
-	const ACCENT = '#cdf24e';
+	const ACCENT = $derived($accent.value);
 
 	let url = $state('');
 	let audioMode = $state<AudioMode>('auto');