Neither limit had any coverage: a renderer that emits more than 4K and
a program that introduces more than 4096 run-time names are both past
anything the corpus does, so the truncation and the abort were code
that had never executed. dev_limits.c drives them directly — they are C
entry points with no Flan spelling, and flan_dev.c is compiled into
every build — one process per mode, because the name table never
shrinks and the overflow case aborts.
The cap case pins the length, the ellipsis, a byte from before the cut,
the generation moving exactly once, and the flag being cleared so a
short value after a truncated one does not inherit its ellipsis. The
registry case pins that 4096 fit and the next one stops the process
with its reason. Dropping result_full and moving the slot check by one
were both planted and watched fail.