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>

backend/models/types.go

@@ -0,0 +1,31 @@
+package models
+
+// Channel represents a single IPTV channel parsed from an M3U playlist.
+type Channel struct {
+	ID        string `json:"id"`
+	Name      string `json:"name"`
+	Group     string `json:"group"`
+	LogoURL   string `json:"logo_url"`
+	StreamURL string `json:"stream_url"`
+}
+
+// StreamStatus represents the current streaming state.
+type StreamStatus struct {
+	Source      string `json:"source"`       // "obs" or "iptv"
+	ChannelName string `json:"channel_name"` // current IPTV channel name (empty if OBS)
+	Live        bool   `json:"live"`
+}
+
+// ProcessInfo represents the status of a managed child process.
+type ProcessInfo struct {
+	Running bool   `json:"running"`
+	PID     int    `json:"pid"`
+	Uptime  string `json:"uptime"`
+	Error   string `json:"error,omitempty"`
+}
+
+// SystemStatus holds status for all managed processes.
+type SystemStatus struct {
+	MediaMTX ProcessInfo `json:"mediamtx"`
+	FFmpeg   ProcessInfo `json:"ffmpeg"`
+}