Fix day/night length application in NTimeManager

[VibeCodeMonster]

Motivation

• The plugin sometimes failed to apply day/night durations to the TOD cycle and printed "Could not apply day/night lengths via TOD cycle parameters.".
• Servers that ignore direct TOD cycle values still accept console env variables, so a fallback is needed to reliably set durations.

Description

• Refreshes the TOD cycle after setting cycle fields by adding TryRefreshCycle(sky.Cycle) which invokes Refresh or Update if available.
• Adds a fallback that sets console variables env.daylength and env.nightlength via ConsoleSystem.Run.Server.Quiet using TrySetEnvLength when direct cycle members are not effective.
• Uses invariant formatting with CultureInfo.InvariantCulture when sending float values to the console to avoid locale issues.
• Adjusts the warning logic to only warn if both the cycle and env fallbacks failed to apply lengths.

Testing

• No automated tests were run for this change.

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Codex Task