[BUG]ReplaceableEventStrategy sends an empty error string to clients on DB failure #710

Describe the bug

In src/handlers/event-strategies/replaceable-event-strategy.ts, the catch block emits an error: prefix with no message body:

createCommandResult(event.id, false, 'error: ')  // ← trailing space, no message

Clients receive ["OK", "<id>", false, "error: "] with no actionable information. The actual error.message is silently swallowed.

Fix

createCommandResult(event.id, false, `error: ${error.message}`)

System: Linux, Docker