fix(init): make home preparation complete and retryable

[ss-o]

Problem

.zi-prepare-home marks initialization complete before its directory work succeeds, and creates ZI[SERVICES_DIR] only when ZI[SNIPPETS_DIR] is absent.

Current source:

• zi/zi.zsh

  Lines 1172 to 1236 in 7956627

  	.zi-prepare-home() {
  	[[ -n ${ZI[HOME_READY]} ]] && return
  	ZI[HOME_READY]=1
  	if [[ ! -d ${ZI[HOME_DIR]} ]]; then
  	command mkdir -p "${ZI[HOME_DIR]}"
  	command chmod 700 "${ZI[HOME_DIR]}"
  	fi
  	# Set up $ZPFX
  	if [[ ! -d ${ZPFX}/bin ]]; then
  	command mkdir -p "${ZPFX}/bin"
  	fi
  	if [[ ! -d ${ZPFX}/lib ]]; then
  	command mkdir -p "${ZPFX}/lib"
  	command chmod go-w "${ZPFX}/lib"
  	fi
  	if [[ ! -d ${ZPFX}/share ]]; then
  	command mkdir -p "${ZPFX}/share"
  	command chmod go-w "${ZPFX}/share"
  	fi
  	if [[ ! -d ${ZI[MAN_DIR]} ]]; then
  	command mkdir 2>/dev/null -p ${~ZI[MAN_DIR]}/man{1..9}
  	command chmod -R go-w "${ZI[MAN_DIR]}"
  	fi
  	if [[ ! -d ${ZI[CACHE_DIR]} ]]; then
  	command mkdir -p "${ZI[CACHE_DIR]}"
  	command chmod 700 "${ZI[CACHE_DIR]}"
  	fi
  	if [[ ! -d ${ZI[CONFIG_DIR]} ]]; then
  	command mkdir -p "${ZI[CONFIG_DIR]}"
  	command chmod 700 "${ZI[CONFIG_DIR]}"
  	fi
  	if [[ ! -d ${ZI[LOG_DIR]} ]]; then
  	command mkdir -p "${ZI[LOG_DIR]}"
  	command chmod 700 "${ZI[LOG_DIR]}"
  	fi
  	if [[ ! -d ${ZI[ZMODULES_DIR]} ]]; then
  	command mkdir -p "${ZI[ZMODULES_DIR]}"
  	command chmod go-w "${ZI[ZMODULES_DIR]}"
  	fi
  	if [[ ! -d ${ZI[PLUGINS_DIR]}/_local---zi ]]; then
  	command rm -rf "${ZI[PLUGINS_DIR]:-${TMPDIR:-/tmp}/132bcaCAB}/_local---zi"
  	command mkdir -p "${ZI[PLUGINS_DIR]}/_local---zi"
  	command chmod go-w "${ZI[PLUGINS_DIR]}"
  	command ln -s "${ZI[BIN_DIR]}/lib/_zi" "${ZI[PLUGINS_DIR]}/_local---zi"
  	(( ${+functions[.zi-setup-plugin-dir]} )) || builtin source "${ZI[BIN_DIR]}/lib/zsh/install.zsh" || return 1
  	(( ${+functions[.zi-confirm]} )) || builtin source "${ZI[BIN_DIR]}/lib/zsh/autoload.zsh" || return 1
  	.zi-clear-completions &>/dev/null
  	.zi-compinit 1 &>/dev/null
  	fi
  	if [[ ! -d ${ZI[COMPLETIONS_DIR]} ]]; then
  	command mkdir "${ZI[COMPLETIONS_DIR]}"
  	command chmod go-w "${ZI[COMPLETIONS_DIR]}"
  	# Symlink _zi completion into _local---zi directory.
  	command ln -s "${ZI[PLUGINS_DIR]}/_local---zi/_zi" "${ZI[COMPLETIONS_DIR]}"
  	(( ${+functions[.zi-setup-plugin-dir]} )) || builtin source "${ZI[BIN_DIR]}/lib/zsh/install.zsh" || return 1
  	.zi-compinit 1 &>/dev/null
  	fi
  	if [[ ! -d ${ZI[SNIPPETS_DIR]} ]]; then
  	command mkdir -p "${ZI[SNIPPETS_DIR]}/OMZ::plugins"
  	command chmod go-w "${ZI[SNIPPETS_DIR]}"
  	( builtin cd -q ${ZI[SNIPPETS_DIR]}; command ln -s OMZ::plugins plugins; )
  	command mkdir -p "${ZI[SERVICES_DIR]}"
  	command chmod go-w "${ZI[SERVICES_DIR]}"
  	fi
  	} # ]]]

Reproduction evidence

With an isolated Zi root where snippets/ already existed and services/ did not, sourcing Zi completed but the service directory remained absent:

service_dir_rc=1

Several directory commands also do not propagate failure, while ZI[HOME_READY]=1 prevents a later retry.

Impact

Partial, migrated, or manually repaired layouts can be accepted as ready. Service startup then tries to create locks and FIFOs below a missing directory, and transient initialization failures can persist for the shell session.

Acceptance criteria

• Establish and validate each required directory independently.
• Propagate creation, permission, link, and initialization failures.
• Set ZI[HOME_READY] only after successful completion.
• Leave retry possible after a failed preparation.
• Add tests for partial layouts, existing paths, permission failure, and retry.

Next action

Define the complete home-layout invariant, then make preparation transactional at the function level.

[ss-o]

Fixed by #509, merged to next.

The services directory now has its own condition rather than being created as a side effect of creating the snippets directory, the required set is validated before readiness is recorded, and ZI[HOME_READY] is set only after that passes, so a failure names the missing directory and stays retryable.

$ZPFX and the manual directory stay best-effort by design: they are user-facing install prefixes rather than Zi state, and the manual tree has always tolerated a creation failure. Promoting them to required would turn a read-only prefix into a startup failure for shells that work today.

tests/home-preparation.zsh covers the partial layout, an uncreatable required directory, the retry, and the no-op on an already-ready home. Against the previous function it reports partial layout: the services directory was not created.

Closing here rather than on merge, since Closes only fires against the default branch and this landed on next.