Update: strict-mode migrations, per-file completion markers

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QKxGW1raAWaqeU8WdHsMsp

bin/omarchy-cn-update

@@ -5,7 +5,7 @@
 set -euo pipefail
 
 MANIFEST="$HOME/.local/state/omarchycn/overlay-manifest"
-MIGRATION_STATE="$HOME/.local/state/omarchycn/last-migration"
+MIGRATION_DONE_DIR="$HOME/.local/state/omarchycn/migrations-done"
 
 if [[ ! -f $MANIFEST ]]; then
   echo "Not an overlay install (no $MANIFEST)." >&2
@@ -26,20 +26,16 @@ echo "Source: $old -> $new"
 
 "$src/bin/omarchy-cn-install-overlay"
 
-# Run migrations newer than the last recorded one, in filename order
-last=""
-if [[ -f $MIGRATION_STATE ]]; then
-  last=$(<"$MIGRATION_STATE")
-fi
-
+# Run each not-yet-completed migration in filename order, one marker per file
 if [[ -d $src/cn/migrations ]]; then
+  mkdir -p "$MIGRATION_DONE_DIR"
   for m in "$src"/cn/migrations/*.sh; do
     [[ -f $m ]] || continue
     name="${m##*/}"
-    if [[ $name > $last ]]; then
+    if [[ ! -f $MIGRATION_DONE_DIR/$name ]]; then
       echo "Migration: $name"
-      bash "$m"
-      echo "$name" > "$MIGRATION_STATE"
+      bash -euo pipefail "$m"
+      touch "$MIGRATION_DONE_DIR/$name"
     fi
   done
 fi