fix(shell): let bash-preexec install last so atuin preexec fires

Eagerly calling __bp_install at source time made bash-preexec install
before starship/atuin/zoxide/ghostty modified PROMPT_COMMAND, so their
hooks landed after __bp_interactive_mode. bash-preexec then never marked
typed commands as interactive and skipped preexec_functions, so atuin's
__atuin_preexec never fired and history stopped recording
(ATUIN_PREEXEC_BACKEND stuck at "<shlvl>:none").

Remove the eager __bp_install and the manual PROMPT_COMMAND/array wiring
for starship, atuin and zoxide; each tool registers with bash-preexec
itself, and deferred install on the first prompt keeps
__bp_interactive_mode last (verified against bash-preexec 0.6.0).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

scripts/shell-init.sh

@@ -19,20 +19,6 @@ is_interactive() {
   [[ -t 1 || -n ${PS1:-} ]]
 }
 
-append_unique() {
-  local var="$1" val="$2"
-  [[ ";${!var:-};" == *";$val;"* ]] && return
-  printf -v "$var" '%s' "${!var:+${!var%;};}$val"
-}
-
-prepend_unique_array() {
-  local name="$1" val="$2"
-  local -n arr="$name"
-  local out=("$val")
-  for f in "${arr[@]}"; do [[ $f != "$val" ]] && out+=("$f"); done
-  arr=("${out[@]}")
-}
-
 # ---- environment sanity ----------------------------------------------------
 
 if [[ -z ${TERM:-} || $TERM == dumb ]]; then
@@ -56,7 +42,10 @@ fi
 if [[ -n ${BASH_VERSION:-} && -z ${bash_preexec_imported:-} && -r "@BASHPREEXEC@" ]]; then
   # shellcheck disable=SC1090
   . "@BASHPREEXEC@"
-  have __bp_install && __bp_install
+  # Do NOT call __bp_install here. bash-preexec must install on the FIRST prompt,
+  # after starship/atuin/zoxide/ghostty have modified PROMPT_COMMAND, so that
+  # __bp_interactive_mode stays the LAST PROMPT_COMMAND entry. Installing eagerly
+  # lets later hooks land after it and silently breaks preexec (atuin recording).
   log_shell_init "bash-preexec loaded"
 fi
 
@@ -68,7 +57,8 @@ if have @STARSHIP@; then
     */bash) eval "$(@STARSHIP@ init bash)" ;;
     */zsh)  eval "$(@STARSHIP@ init zsh)" ;;
   esac
-  append_unique PROMPT_COMMAND starship_precmd
+  # starship's bash init registers starship_precmd/starship_preexec_all with
+  # bash-preexec directly; no manual PROMPT_COMMAND wiring needed.
 else
   log_shell_init "starship skipped"
 fi
@@ -87,10 +77,8 @@ if have @ATUIN@; then
     */bash) eval "$(@ATUIN@ init bash)" ;;
     */zsh)  eval "$(@ATUIN@ init zsh)" ;;
   esac
-
+  # atuin's init registers __atuin_preexec/__atuin_precmd with bash-preexec
-  declare -a preexec_functions precmd_functions
+  # itself; manual array wiring only caused duplicate hook entries.
-  prepend_unique_array preexec_functions __atuin_preexec
-  prepend_unique_array precmd_functions  __atuin_precmd
 else
   log_shell_init "atuin skipped"
 fi
@@ -103,16 +91,13 @@ if have zoxide; then
     */bash) eval "$(zoxide init bash)" ;;
     */zsh)  eval "$(zoxide init zsh)" ;;
   esac
-  have __zoxide_hook && append_unique PROMPT_COMMAND __zoxide_hook
+  # zoxide's bash init hooks into bash-preexec (precmd_functions) when it is
+  # present; manual PROMPT_COMMAND wiring only pushed hooks past
+  # __bp_interactive_mode and broke preexec ordering.
 else
   log_shell_init "zoxide skipped"
 fi
 
-# ---- bash-preexec PROMPT_COMMAND safety -----------------------------------
-
-have __bp_precmd_invoke_cmd && append_unique PROMPT_COMMAND __bp_precmd_invoke_cmd
-have __bp_interactive_mode   && append_unique PROMPT_COMMAND __bp_interactive_mode
-
 # ---- aliases --------------------------------------------------------------
 
 if have eza; then