Fixed

• LuckTAB did not start on Spigot. The text renderer, the tab list and the sidebar were written against Adventure and Paper-only methods, and Spigot ships neither, so the plugin died during startup before its command executor was registered. The command stayed registered without an executor, which is why /lucktab reload and /lucktab migrate answered with nothing but the /lucktab <reload|migrate> usage line from plugin.yml, while the tab list, the name tags and the sidebar stayed empty. Rendering now runs on the Bukkit API with legacy color codes on every server, and the Adventure calls are isolated in a class that is only loaded on Paper.
• A failed start left the plugin marked as enabled. Spigot keeps a plugin enabled when its startup throws, so the broken state was silent apart from one line in the log. Startup errors now disable the plugin and say why.
• /lucktab required lucktab.reload for every subcommand, including the migration and the help output. It checks lucktab.use now, and lucktab.reload only where it actually reloads.

Added

• Tab completion for /lucktab, for the subcommands and for the migration directions.

Paper servers were never affected by the startup bug and keep the component based scoreboard lines and the chat renderer.