Add CLI arguments for session simulation replay

[Abasz]

Description:

This replaces the commented-out simulation block in server.js with proper CLI arguments, enabling replay of recorded rowing sessions without modifying source code.

What changed

• Extracted CLI argument parsing into SimulationArgs.js
• server.js conditionally activates simulation only when --simulate is passed
• Added npm run simulate convenience script to package.json
• Added unit tests for all argument combinations in SimulationArgs.test.js
• It uses Node's built in parse argument helper that is robust

Defaults preserve current behavior

All defaults match the original commented-out block exactly:

• File: Concept2_RowErg_Session_2000meters.csv
• Delay: 30000ms
• Realtime: enabled
• Looping: enabled

Without --simulate, the server behaves identically to before — this is a zero-impact change for production.

Available flags

Flag	Description
--simulate	Enable session replay
--simulateFile <path>	Override the default recording file
--simulateDelay <ms>	Override the startup delay
--simulateOnce	Run the replay once instead of looping
--simulateFast	Replay at maximum speed instead of realtime

Benefits over the old approach

• No source code changes needed — no risk of accidentally committing an uncommented debug block
• Flexible — file path, delay, looping, and speed are all configurable per invocation
• Testable — parsing logic is isolated and covered by 7 unit tests
• Discoverable — npm run simulate makes it easy for new contributors to find

Example usage

# Default simulation (same as the old commented block)
node app/server.js --simulate

# Custom file, fast, single run
node app/server.js --simulate --simulateFile recordings/WRX700_2magnets.csv --simulateFast --simulateOnce