split audio/subtitle concerns, remove docker-in-docker, add per-node path mapping

- install ffmpeg in dockerfile (fixes exit code 127)
- buildCommand() now audio-only remux, no subtitle extraction
- add unapprove endpoint + ui button for approved items
- add batch extract-all subtitles endpoint + ui button
- audio detail page shows only video+audio streams
- remove global movies_path/series_path config, add per-node path mapping
- remove docker-in-docker command building (buildDockerCommand, buildDockerExtractOnlyCommand)
- ssh execution translates /movies/ and /series/ to node-specific paths
- remove media paths section from setup page
- add unraid-template.xml

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

Dockerfile

@@ -6,13 +6,14 @@ COPY . .
 RUN npx vite build
 
 FROM oven/bun:1
+RUN apt-get update && apt-get install -y --no-install-recommends ffmpeg && rm -rf /var/lib/apt/lists/*
 WORKDIR /app
 COPY package.json bun.lock* ./
 RUN bun install --frozen-lockfile --production
-COPY --from=build /app/dist ./dist
-COPY --from=build /app/server ./server
+COPY --from=build /app/dist/ ./dist/
+COPY --from=build /app/server/ ./server/
 EXPOSE 3000
-ENV DATA_DIR=/data
+ENV DATA_DIR=/data/
 ENV PORT=3000
-VOLUME ["/data"]
+VOLUME ["/data/"]
 CMD ["bun", "run", "server/index.tsx"]