Refactor load testing scripts to support Bash and PowerShell

- Updated README.md to reflect changes in load testing commands and added usage examples for Bash scripts.
- Converted PowerShell load testing scripts to Bash equivalents for better cross-platform compatibility.
- Added new Bash scripts: run-loadtests.sh, summarize-artillery.sh, and summarize-k6.sh to mirror existing PowerShell functionality.
- Updated admin-api.js and ws-chat.yml for consistency and improved performance metrics reporting.
- Enhanced error handling and output formatting in summary scripts for better readability.

backend/chat/Dockerfile

@@ -1,17 +1,17 @@
-FROM golang:1.25-alpine AS builder
-
-RUN apk add --no-cache gcc musl-dev
-
-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 curl ffmpeg
-WORKDIR /app
-COPY --from=builder /chat-server /usr/local/bin/chat-server
-
-EXPOSE 3000
+FROM golang:1.25-alpine AS builder
+
+RUN apk add --no-cache gcc musl-dev
+
+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 curl ffmpeg
+WORKDIR /app
+COPY --from=builder /chat-server /usr/local/bin/chat-server
+
+EXPOSE 3000
 CMD ["/usr/local/bin/chat-server"]