Temp4Boost

Added /t4b active for players to view their active boosts and remaining time in chat.
Added fully configurable chat formatting for active boost output in config.yml.
Expanded PlaceholderAPI support with more display-friendly placeholders and configurable output formats.
Improved reload safety: reload now aborts cleanly if config.yml is missing, unreadable, or invalid.
Improved runtime recovery to keep the previous safe state when a reload fails.
Hardened active boost persistence and save-on-change rollback handling.
Improved protection against desyncs with active boosts after join, respawn, world change, gamemode change, milk, and external effect updates.
Reduced false-positive warnings and refined console diagnostics.
Improved update checker behavior while keeping the stable Spigot legacy endpoint.
Improved general config polish, placeholder display defaults, and current config version handling.
Verified compatibility builds across the supported Paper range from 1.18.2 to 1.21.11.