Implement Tuner v1 — Go backend, React frontend, Docker setup

- Go backend: REST API, M3U parser, FFmpeg/MediaMTX process manager
- React/Vite frontend: HLS player, admin panel, channel browser (dark theme)
- MediaMTX config for RTMP ingest + HLS output
- Multi-stage Dockerfile (Go + Bun + Alpine runtime)
- docker-compose.yml for single-container deployment
- Sample M3U playlist with test streams

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

Dockerfile

@@ -0,0 +1,35 @@
+# Stage 1: Build Go backend
+FROM golang:1.23-alpine AS backend
+WORKDIR /src
+COPY backend/ .
+RUN go build -o /out/tuner .
+
+# Stage 2: Build React frontend
+FROM oven/bun:latest AS frontend
+WORKDIR /src
+COPY frontend/ .
+RUN bun install && bun run build
+
+# Stage 3: Runtime
+FROM alpine:3.20
+RUN apk add --no-cache ffmpeg ca-certificates wget tar \
+    && wget -qO /tmp/mediamtx.tar.gz \
+       https://github.com/bluenviron/mediamtx/releases/download/v1.12.2/mediamtx_v1.12.2_linux_amd64.tar.gz \
+    && tar -xzf /tmp/mediamtx.tar.gz -C /usr/local/bin mediamtx \
+    && rm /tmp/mediamtx.tar.gz \
+    && apk del wget tar
+
+WORKDIR /app
+COPY --from=backend /out/tuner /app/tuner
+COPY --from=frontend /src/dist /app/frontend/dist
+COPY mediamtx.yml /app/mediamtx.yml
+
+ENV RESTREAMER_PORT=8080
+ENV PLAYLIST_PATH=/data/playlist.m3u
+ENV MEDIAMTX_PATH=/usr/local/bin/mediamtx
+ENV MEDIAMTX_CONFIG=/app/mediamtx.yml
+ENV FRONTEND_DIR=/app/frontend/dist
+
+EXPOSE 1935 8080 8888
+
+ENTRYPOINT ["/app/tuner"]