Objective: Add a configurable timeout for executing a single move/command with safe cancellation and surfaced error.

Context:

• Likely in src/server/command/executor.ts and src/server/command/move-piece.ts.
• Consider backoff/retry policy vs fail-fast; ensure robot state and game state remain consistent on timeout.

Acceptance:

• Timeout duration is configurable; exceeded timeouts cancel in-flight move and report failure via API/socket.
• No partial state is left inconsistent; next moves can proceed safely.
• Simulator scenario demonstrates a timeout and recovery.