- shfunc_call (zle/compcore.rs:3817): route through
  exec_hooks::dispatch_function_call instead of just probing
  for the function and returning the stale LASTVAL. The fusevm
  bridge installs the dispatcher fn-ptr at startup so completion
  code (compcore) calling compfunc/etc. actually executes the
  shell function body instead of no-op'ing with last status.
  Fallback to LASTVAL when hook isn't installed (executor not
  yet up).

- describekeybriefly (zle/zle_main.rs:1024): C-name-parity entry
  delegates to the snake-cased describe_key_briefly (real
  substrate) instead of returning 1. Was a hard-coded "no
  resolution" stub.

Also cleaned stale narrative comments in signals.rs settrap.