Preserve local Elsewhen work and fallback bar layouts

Retire only checkouts whose refs and reflogs are reachable from recorded origin history, and preserve ignored files. Leave configs without an explicit supported bar layout untouched so migration does not replace the shell fallback with an almost empty bar.

Co-Authored-By: Codex XHigh <noreply@openai.com>

test/shell.d/elsewhen-default-migration-test.sh

@@ -156,6 +156,18 @@ run_migration
 [[ ! -e $config ]] || fail "migration writes no shell.json where the defaults apply" "$(cat "$config")"
 pass "migration writes no shell.json where the defaults apply"
 
+for partial in \
+  '{"version":1,"idle":{"lock":600}}' \
+  '{"version":1,"bar":null,"idle":{"lock":600}}' \
+  '{"version":1,"bar":{"position":"bottom"}}' \
+  '{"bar":{"layout":{"center":["omarchy.clock"]}}}'; do
+  printf '%s\n' "$partial" >"$config"
+  before=$(sha256sum "$config")
+  run_migration
+  [[ $before == $(sha256sum "$config") ]] || fail "migration preserves fallback configuration" "$(cat "$config")"
+  pass "migration preserves fallback configuration: $partial"
+done
+
 printf '{ not json' >"$config"
 run_migration
 [[ $(cat "$config") == '{ not json' ]] || fail "migration leaves an unparsable config untouched" "$(cat "$config")"
@@ -201,6 +213,7 @@ make_checkout() {
   printf 'import QtQuick\nItem {}\n' >"$checkout/Panel.qml"
   git -C "$checkout" add -A
   git -C "$checkout" commit -q -m "Elsewhen"
+  git -C "$checkout" update-ref refs/remotes/origin/main HEAD
 }
 
 reset_layout() {
@@ -257,6 +270,62 @@ reset_layout
 run_migration
 assert_kept "a clone with an untracked file"
 
+make_checkout https://github.com/omacom/elsewhen.git
+printf 'import QtQuick\nItem { id: mine }\n' >"$checkout/Panel.qml"
+git -C "$checkout" add Panel.qml
+git -C "$checkout" commit -q -m "Local customization"
+local_commit=$(git -C "$checkout" rev-parse HEAD)
+reset_layout
+run_migration
+assert_kept "a clean clone with an unpublished commit"
+[[ $(git -C "$checkout" rev-parse HEAD) == "$local_commit" ]] || fail "local commit survives"
+
+make_checkout https://github.com/omacom/elsewhen.git
+git -C "$checkout" checkout -qb local-work
+printf 'local branch\n' >"$checkout/Panel.qml"
+git -C "$checkout" commit -qam "Unpublished branch"
+git -C "$checkout" checkout -q --detach refs/remotes/origin/main
+reset_layout
+run_migration
+assert_kept "an unpublished commit on another branch"
+
+make_checkout https://github.com/omacom/elsewhen.git
+printf 'stashed work\n' >"$checkout/Panel.qml"
+git -C "$checkout" stash push -q
+reset_layout
+run_migration
+assert_kept "a clean clone with stashed work"
+
+make_checkout https://github.com/omacom/elsewhen.git
+git -C "$checkout" config status.showUntrackedFiles no
+printf 'private-notes\n' >"$checkout/.git/info/exclude"
+printf 'ignored work\n' >"$checkout/private-notes"
+reset_layout
+run_migration
+assert_kept "a clone with an ignored file"
+[[ $(cat "$checkout/private-notes") == "ignored work" ]] || fail "ignored file survives"
+
+make_checkout https://github.com/omacom/elsewhen.git
+printf 'recoverable work\n' >"$checkout/Panel.qml"
+git -C "$checkout" commit -qam "Recoverable local commit"
+git -C "$checkout" reset -q --hard refs/remotes/origin/main
+reset_layout
+run_migration
+assert_kept "a local commit retained only by the reflog"
+
+make_checkout https://github.com/omacom/elsewhen.git
+git -C "$checkout" update-ref -d refs/remotes/origin/main
+reset_layout
+run_migration
+assert_kept "a clone without recorded upstream history"
+
+make_checkout https://github.com/omacom/elsewhen.git
+git -C "$checkout" config status.showUntrackedFiles no
+printf 'untracked work\n' >"$checkout/NOTES.md"
+reset_layout
+run_migration
+assert_kept "untracked files hidden by the user Git configuration"
+
 make_checkout https://github.com/someone/elsewhen-fork.git
 reset_layout
 run_migration