update environment configuration, enhance setup guide, and align documentation with new domain structure

backend/chat/Dockerfile

@@ -1,17 +1,17 @@
 FROM golang:1.23-alpine AS builder
 
-WORKDIR /app
-COPY src/ ./src/
-COPY go.mod go.sum ./
+RUN apk add --no-cache gcc musl-dev
 
-RUN go mod download
-RUN CGO_ENABLED=0 GOOS=linux go build -o /chat-server ./src/main.go
+WORKDIR /app
+COPY go.mod ./
+COPY src/ ./src/
+RUN go mod tidy
+RUN CGO_ENABLED=1 GOOS=linux go build -o /chat-server ./src/main.go
 
 FROM alpine:3.20
 RUN apk --no-cache add ca-certificates
 WORKDIR /app
-COPY --from=builder /chat-server .
-COPY config/ ./config/
+COPY --from=builder /chat-server /usr/local/bin/chat-server
 
 EXPOSE 3000
-CMD ["./chat-server"]
+CMD ["/usr/local/bin/chat-server"]

backend/playout/Dockerfile

@@ -1,8 +1,7 @@
-FROM golang:1.23-alpine AS builder
+FROM golang:1.25-alpine AS builder
 
 WORKDIR /app
 COPY src/ ./src/
-COPY go.mod go.sum ./
 
 # Initialize Go module if not present
 RUN go mod init playout || true

backend/playout/src/playlist.go

@@ -75,7 +75,7 @@ func ValidateVideo(videoPath string) (VideoFile, error) {
 	v := VideoFile{Path: videoPath}
 
 	cmd := exec.Command("ffprobe", "-v", "quiet", "-print_format", "json", "-show_format", "-show_streams", videoPath)
-	output, err := cmd.Output()
+		_, err := cmd.Output()
 	if err != nil {
 		v.Validation = "ffprobe failed: " + err.Error()
 		return v, err