fix(compiler): the built-in ECS stops at its 1024th entity instead of writing past every store

L_alloc handed out a fresh slot without a bound, so the 1025th spawn wrote past the end of every
component array. It stops with a located message naming the store's size and where many things
belong (ludic.base's Table). Growable stores are plan 24.8: the save, rollback snapshot and mod
table write the stores whole at a compile-time size, so that is a file-format change. Reseeded;
ludic-dev test 305 passed, selfhost-test 33 passed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

changes/ecs-entity-overflow.md

@@ -0,0 +1,7 @@
+bump: patch
+type: fix
+**The 1,025th entity stops the program instead of corrupting it.** The built-in ECS keeps every
+component in a fixed array of 1024 slots, and `L_alloc` never checked: one entity more was written
+past the end of every component array at once. A spawn past the store now stops with `more than
+1024 entities: the built-in ECS holds 1024; keep many things in a ludic.base Table`. A game that
+keeps thousands of something keeps them as rows of `ludic.base`'s `Table<T>`, which grows.