Better /summon

Better /summon 1.1.1

Hardening pass on the batched-spawn path. No new commands, no syntax changes — everything you already type still works, it just behaves better under stress.

Fixed

• Queue overflow. The batched-spawn queue could grow without bound if a command block or RCON client fired long /summon … <count> calls rapidly. The queue is now capped at 20 pending batched tasks and returns a clear command error when full instead of silently consuming memory.
• Stale task carry-over between single-player sessions. Pending tasks from a previous integrated-server session could point at a world that no longer exists. The queue is now reset on SERVER_STARTING (not only on stop), and every batch re-verifies the source server is still running before processing the next tick.
• Redundant empty-NBT clones. When no <nbt> argument was given, the mod was still deep-copying an empty NBT compound for every entity — 100 throwaway allocations per tick at full batch speed. It now reuses a shared empty compound on the common path.

Changed

• Documented the ACTIVE_TASKS thread-safety contract (server-thread only) so future refactors preserve the invariant.
• Rewrote README.md with a full command reference, a description of how batching works, and the guardrails applied to every argument.
• Corrected a docs bug: the earlier README claimed random used SecureRandom. It does not — it uses ThreadLocalRandom (uniform, non-cryptographic). Same behaviour, accurate description.

Unchanged

• All six command overloads (/summon <entity> <count>, … random <min> <max>, the <pos> and <nbt> variants) behave exactly as before for valid input.
• Permission level, 1..10_000 bounds, and min > max error behaviour are identical.
• Server-side only; clients do not need the mod.